Based on the blizzard of images and sound bites in this fall's campaigns, American voters might think they face impossible choices in the midterm election. The year's candidates have presented them with a picture not just of contrasts, but of extremes: the one who gives succor to terrorists vs. the one who is indifferent to the death of soldiers in Iraq; a politician in the pocket of big oil vs. one who would let gas prices rise until average Americans are no longer able to drive cars; a candidate who would open the border to potentially dangerous "aliens" vs. an advocate of an immigration policy so rigid it would strangle the American economy.

"Americans are under attack from Islamic extremists in every corner of the world. Homosexuals are mocking holy matrimony, and the lesbians and feminists are attacking everything sacred. Liberal judges have completely rewritten the Constitution," a narrator intones against the eerie theme song of the old "Twilight Zone" TV show in a television ad airing in the North Carolina district represented by Democratic Rep. Brad Miller. His long-shot challenger, Republican Vernon Robinson, appears at the end of the ad, promising to send those "realities" back to the Twilight Zone.

In New Jersey, two state legislators running for an open House seat have accused each other of helping criminals. In Wisconsin, the Republican challenger to Democratic Rep. Ron Kind calls the incumbent the "wrong kind," who voted to allow illegal immigrants to burn flags as protests and to finance federal research of trans-gender Eskimos. In a new ad airing in several competitive districts and paid for by a group supporting stem cell research, a cherubic young girl says she will soon be diagnosed with diabetes and asks why certain members of Congress "get to decide" who lives and who dies.

Tens of millions of dollars are being poured into the negative ads that inundate voters by television, radio, Internet and telephone, often fueled by outside groups or party organizations so that the candidates themselves can say their own campaigns remain above the fray. According to data compiled by CQ's PoliticalMoneyLine, which tracks campaign receipts and expenditures, of $67.4 million spent by interest groups including the national party organizations as of early last week, more than 80 percent — $56 million — has been spent on attacks.

Running down the other guy has been a staple of closely contested American campaigns since John Adams questioned Thomas Jefferson's family values. But academics, political operatives and their client candidates say a number of factors have all converged to make 2006 the nastiest election in the modern era.

The federal campaign finance overhaul enacted in 2002 sought to stem the amount of cash flowing to negative advertising, but it instead was diverted into the independent expenditures so heavily used this election cycle by the parties and interest groups to drive home nationally orchestrated strategies. And those messages are often the negative ones.

One important factor in the stream of attacks is the closeness, nationwide, of this year's battle between the Republicans and Democrats for control of Congress. Politicians in tight races are looking not only to sell their own candidacies, but also to seal the deal by turning the voters against their opponents. There is, additionally, a dearth of good news to promote, and analysts say neither party has much of a "good news" agenda on which to run.

Finally, the flavor of corruption and scandal this year — relating to lobbyist Jack Abramoff, former House Majority Leader Tom DeLay and most recently Mark Foley — has further brought a negative dynamic to the campaign. These episodes make it easy for politicians to go on the attack, particularly Democrats trying to feed the anti-incumbent mood of the year.

Higher Stakes, Lower Standards

A candidate who is way ahead in the polls has some incentive to avoid disturbing the water and instead let the muck sit on the bottom until Election Day. But when an election is close, both sides fight hard. And this year, the margins are razor thin, with control of Congress — and with it the ability to advance or thwart the Bush administration's agenda — in the balance.

Democrats are clearly within sight of picking up the 15 seats they need to take control of the House, and they also have a plausible shot at the six-seat gain that would deliver the Senate. Republicans are now leading in only 209 House races, nine shy of the 218 needed to hold control, which means their only way to hold power is to dominate the tossup contests on Nov. 7 — which could prove impossible if the recent political tide away from the GOP and toward the Democrats continues for the next three weeks.

Republican fortunes are a bit brighter in the Senate, where the GOP is currently on course to win enough races to claim 49 seats next year, with five contests too close to call. But there, too, Democrats appear to have momentum. Lincoln Chafee of Rhode Island has now joined Rick Santorum of Pennsylvania as a clear Republican underdog for re-election. Three other GOP incumbents — Conrad Burns of Montana, Mike DeWine of Ohio and Jim Talent of Missouri — are all clinging to their current too-close-to-call status.

But the problems facing candidates of both parties are significant. Voters' opinion of Congress is bottoming out, and neither party has much of an agenda to run on, according to John G. Geer, a political science professor at Vanderbilt University and author of "In Defense of Negativity," a book in which he argues that voters can actually benefit from a negative campaign. This year, Geer says, the lack of positive ideas plays into the negativity.

"Republicans are plagued by Iraq, by gas prices, high deficit, et cetera, and the Democrats frankly don't have a coherent message," he said. "It's not really clear what they would do in Iraq. It's not clear what they would do on security and various issues like that," Geer said. But, he added, "they certainly can raise doubts about the other side. And there will be as a result a huge outpouring of negative ads."

In this environment, the parties have done just as Geer predicted. This fall, the National Republican Congressional Committee, the House GOP campaign arm, announced its intention to use the vast majority of its substantial treasury digging up dirt on Democratic candidates. In the first week of October alone, the group spent $11.8 million on the campaign — 95 percent of it, or $11.2 million, in opposition to Democrats.

"We're in an environment where voters are taking a mythical positive, and they're supporting that vs. an incumbent," said Dan Hazelwood, president of the GOP media consulting firm Targeted Creative Communications. "But once the voters get shown that the challenger is actually a deeply flawed candidate whose policy positions and career background would be an embarrassment, then they have information to weigh the choices."

For their part, the Democrats are not spending nearly as much, but they are apportioning their outlays the same way: They put $5 million into the campaign between Oct. 1 and Oct. 9, $4.6 million of it in opposition to GOP candidates.

Part of this is an attempt by challengers to seize on what is already a mood of anti-incumbency among the voters, who certainly have a strong sense of the problems facing the country. Polling indicates an electorate unhappy with the state of the country, the war in Iraq and Congress in general. A recent survey by the Pew Research Center found that the anti-incumbent sentiment is stronger than in the previous two midterm elections and near the level of 1994, when Republicans staged their takeover of both houses of Congress.

The Scent of Scandal

The revelations that Foley, while representing a swath of central Florida, sent sexually explicit electronic messages to congressional pages — and that some fellow House Republicans and aides to the GOP leadership knew about his behavior long before he resigned last month — appear to have angered voters even more than this year's public corruption scandals. Those have led to the convictions of several top GOP aides, one-time superlobbyist Abramoff and two Republican members of the House: California's Randy "Duke" Cunningham, who resigned last year, and Ohio's Bob Ney, who formally entered his guilty plea last week.

After the Foley scandal erupted, it was only a matter of days before it showed up in campaign commercials. An ad that began airing last week in several House districts features hand-written words flashing and fading across the screen: "depraved . . . sleazy . . . beastly . . . vile . . . obscene . . ." — 29 in all, each describing the leadership's handling of the matter and, specifically, the role of Rep. Thomas M. Reynolds, the top election strategist for House Republicans and one of the members who knew of Foley's behavior before it became public. The ad ran in Reynolds' upstate New York district, where he's become the underdog, and adapted versions ran in the districts of House Speaker J. Dennis Hastert, whose Illinois seat appears safe, and Deborah Pryce, whose hold on her Ohio seat is becoming further endangered by the Foley scandal.

"Congressman Mark Foley of Florida resigned in disgrace after inappropriate contact with teenage congressional pages," text on the ad reads. "Tom Reynolds knew about Foley's behavior months ago, and said nothing. Republican leaders knew about Foley months ago and swept it under the rug. Speaker Hastert is facing calls to resign. Tell Tom Reynolds and Republican leaders to drop the politics. Tell the truth, or resign."

It is one of a series of spots produced by the soft-fund Democratic group Majority Action to target voters in districts with vulnerable Republican leaders.

Such ads did not begin with the Foley scandal. MoveOn.org, the liberal Internet-based voter mobilization organization that famously poured millions into the 2004 presidential election, bought time for a series of ads after the Abramoff scandal broke that implied that GOP incumbents have been "caught red-handed" in ethically questionable situations.

Revised versions of those ads — now on the air in districts represented by Pryce, Chris Chocola of Indiana, Thelma Drake of Virginia and Nancy L. Johnson of Connecticut — say those Republicans were caught accepting money from drug companies and then voting to defeat a proposal that would have allowed Medicare to negotiate with drug companies on prescription drug prices. For added punch, the screen features photographs of Abramoff and Vice President Dick Cheney, neither of whom was an overt player in the Medicare debate.

But Cheney's visage is a reminder that, all year, public disapproval of the Bush administration has made Republicans scramble to distance themselves from the president — while Democrats seek to highlight their opponents' ties to Bush. In Florida, Democratic State Sen. Ron Klein, who is challenging Republican Rep. E. Clay Shaw Jr., sent a mailer to voters putting the incumbent side by side with the president.

"Wherever George Bush goes, Clay Shaw follows," the piece said. "It's almost like they're the same person." The banner across the top of the mailer includes an amalgam of their names — "BUSHAW" — while a picture below pieces together half of each man's face to create an eerie facsimile of one person.

Republicans and Democrats alike have also departed from what Ronald Reagan referred to as "the 11th Commandment": not to speak ill of a fellow member of the party even when competing in a primary.

This spring, New Jersey state Assembly Speaker Albio Sires and state Rep. Joseph Vas mercilessly battered each other's reputation in their bid for the Democratic nomination for the House seat Robert Menendez vacated when he was appointed to the Senate, despite the fact that the two worked together in the state Legislature. Vas accused Sires of associating with a businessman convicted on fraud charges. Sires countercharged that Vas helped a child molester and drug dealer receive a lighter sentence. "What Joe Vas did wasn't illegal. But it was criminal," a radio ad by the Sires campaign said. (Sires won the primary, which is tantamount to election in the blue-collar suburban district.)

The Party Did It

Part of the impetus for these ads is that candidates are happy to have the outside groups, such as Majority Action and MoveOn.org, do the heavy lifting in attacking their opponents. A principal goal of the sponsors of the four-year-old campaign finance law was to stanch the flow of unregulated cash to mudslinging advertising by the political parties, but what happened instead was that this "soft money" started flowing instead to independent groups, the expenditures of which are on a meteoric rise this year. Outside group spending on campaign ads totaled $25.5 million in September — and $22.8 million in the first nine days of October alone.

Such generosity by independent groups gives candidates plausible deniability about any of the mudslinging contained in their allies' ads, because by law the candidates and the others may not coordinate their messages or their media buys.

Joel Rivlin of the Wisconsin Advertising Project pointed to six-term Republican Rep. John Hostettler, who is defending his Indiana seat against Democratic County Sheriff Brad Ellsworth. While Hostettler describes his campaign as an old-fashioned grass-roots effort, Rivlin says, in fact it has been bolstered by hundreds of thousands of dollars of advertising produced and paid for by the NRCC.

The party committees dole out a steady stream of news releases attacking the opposition and have nearly limitless ability to amplify those attacks — on issues both spurious and germane — through television ads, radio spots, mailers and postings on Internet blogs.

One NRCC mailer against Democrat Patty Wetterling, who is running against state Rep. Michele Bachmann for an open House seat in Minnesota, implied that Wetterling had abdicated her civic duties. "Liberal Patty Wetterling failed to vote in three elections," the mailing said. The truth is more complicated. According to the Minneapolis-St. Paul Star Tribune, she didn't vote in the 2000 or 2002 primaries but voted in the past three general elections.

At the Democratic Congressional Campaign Committee, meanwhile, Chairman Rahm Emanuel of Illinois publicized a letter urging his Republican counterpart, Reynolds, to disavow the candidacy of Randy Graf, who is seeking an open seat in Arizona. "While you and I may have differences of opinion when it comes to policy, certainly we can agree on the right thing to do. Supporting a candidate with ties to the white supremacist community is not the right thing to do," Emanuel wrote.

But those with the most latitude in their attacks are political action committees, nonprofit advocacy organizations and so-called 527 advocacy groups, such as the liberal MoveOn or the conservative Club for Growth, which can still raise and spend unregulated soft money contributions.

Progress for America, a conservative organization that raised $38 million for Bush in 2004, spent $2.7 million in the first six months of 2006 on media production and mailings. Its advertisements have high shock value and were created "to remind Americans of why the U.S. and its allies are fighting the war on terror," the group's Web site says. Since September it has paid for TV spots in Missouri and Ohio, the sites of two of the tossup Senate races, with a montage of graphic images from the war on terrorism and footage of a plane flying into the World Trade Center on Sept. 11.

These groups feel comfortable marketing such hardball attacks, political strategists say, because they are not on the ballot themselves — and in fact are relying only on the continued support of their contributors, who generally like the political groups to which they donate to take a hard line.

Quick on the Draw

But even the help of outside groups is often not enough for the candidates who are feeling particularly imperiled — and who decide that signing their names and faces to harsh attacks is the best way to ensure their political survival. Montana's Burns, for example, turned his ads negative as soon as his opponent, state Senate president and soybean farmer Jon Tester, won the Democratic primary in June.

The first spot described Tester as supported by "radical environmentalists and liberal groups who want to close bases like Malmstrom," an Air Force base in the state. The "radical environmentalist" group cited was the League of Conservation Voters, an organization generally considered moderate. A later ad declared, "Tester's not tough, he's deceitful. He'll say anything to get elected."

In the closing days of his own tight Republican primary campaign last month, Rhode Island's Chafee offered an unusual twist on the theme: he described as unfair his own earlier attack ads on his opponent, which he said he was pushed into by his handlers. (Attacking the attackers, p. 2759)

One of the goals of the campaign finance law was to reduce the amounts of unregulated soft money in campaigns by setting limits for how much could go to both candidates and party committees. The law also required that candidates personally vouch for their own advertising — the ubiquitous "I approved this message" — in the hope that it would tone down the nasty rhetoric.

But as with all new laws, "There's always just a sort of adjustment that takes place on the market level," said Evan Tracey of the TNS Media Intelligence, which specializes in political and public affairs advertising. Like many other strategists, he has concluded that the law does not appear to be working as intended. While the party committees have spent more time than ever raising regulated "hard" money, the soft money they can no longer rake in has simply been diverted from the candidates and the parties to the 527 organizations.

Before the new law, almost all the advertising for a congressional race would be produced and paid for by the candidates themselves, the parties and only a handful of the best-funded interest groups. Now, the proliferation of soft-money-funded groups means that a dozen or more interested players might buy airtime in a single House race. Tracy is predicting that advertising on television alone could run to $1.7 billion in the 2006 election.

And many strategists say the candidate disclaimer requirement has done little to change the tone of the contestants' own messages.

The Value of Negativity

But attack ads are not without their purpose, according to Geer and other analysts. "Democracy requires negativity," Geer said. "If you're going to hold someone accountable, you often have to criticize them. You often have to tell them why they're wrong, point out these problems."

Despite an oft-cited hypothesis, academics have been unable to prove that mudslinging makes voters more likely to stay home on Election Day, and some analysts, including Rivlin of the Wisconsin Advertising Project, maintain that campaigns marked by negativity can elevate voter turnout. "You can find just as many examples where really dirty, nasty races get people excited, and some of the highest turnouts are with the most bitter races. I tend to draw that conclusion — that in a sense it's positive," he said.

Practitioners of the business of politics add that increased voter turnout is their aim. "One of the goals in this business is to try to actually mobilize folks and educate them and to get them out," GOP media consultant Mark Dion said. "The whole purpose of our business is to get people out to the polls to vote for our particular candidate."

Rich Davis of the Democratic Dixon-Davis Media Group added that good ads "respect a voter's ability to think."

Some raise the concern that negative ads are causing increasing polarization in American politics, but Geer said that idea is dead wrong. "The fact that the parties are differing more has provided the grist in the mills for these attacks. To think that advertising would have the ability to polarize this country is giving a huge amount of credit to advertising. It does have effects, but it doesn't have that kind of powerful effect," he said.

Analysts and political consultants echoed Geer's assertion. "The last-minute late hit piece that changes the mind of 20 percent of the electorate is just a myth," said Hazelwood. "Something could show up at the end, but it only works if it's in the context of what's come before it."

'Narrowcasting'

And therein lies one undeniable factor of attack ads: their efficacy.

Advances in marketing have made it possible for campaigns to target sub-segments of populations through the expanding array of media options — known in the trade as "micro-targeting." These niche populations are identified and targeted through a combination of polling data, market research firms, anecdotal evidence from the campaigns and "gut feelings about what's going to work," said Dion, a partner at the Republican media-consulting firm Alfano-Leonardo Communications.

"The days of going after the independent swing voter in many ways are gone," said Rivlin. Candidates "narrowcast" their ads, filming multiple versions of each one to run during television programming targeting different audiences. The increasing array of available outlets gives campaigns the ability to further tailor their pitch to their target.

Davis of Dixon-Davis said he is advising clients to invest a greater percentage of their paid media budgets in cable television, where they can target by demographic or interest, among other variables. "Broadcast television is still an important way to reach the largest number of people as quickly and as loudly as you can if you're trying to introduce a candidate or change the nature of the race, but cable television has become a very targetable tool," he said.

Diverse, specialized audiences make radio another good medium for pitching to specific groups. The National Black Republican Association, which is working to bring African-American voters and politicians into the GOP, recently produced a radio ad supporting Lt. Gov. Michael S. Steele in the Maryland Senate race against Democratic Rep. Benjamin L. Cardin. The spot, which ran on stations across the state with large black audiences, sought to tie the Democratic Party to racist policies including Jim Crow laws and claimed that Democrats started the Ku Klux Klan. "Democrats have bamboozled blacks. . . . Democrats want to keep us poor and voting only Democrat," it said. Steele decried the spot as "insulting to Marylanders" and called for it to be pulled off the air.

Some of the most vicious attack ads arrive via the U.S. Postal Service. Republican media consultant Hazelwood predicted that the average competitive House candidate will spend between 10 percent and 15 percent of his media budget on direct mail, which lacks the emotional connection of TV's moving pictures and sound but gives campaigns the luxury of a longer format to articulate negative messages. The ability to include more supporting documentation lends credibility to a direct-mail attack that might not be persuasive on television, he said.

The Kentucky Republican Party used mailers in the race between Republican Rep. Geoff Davis and Democrat Ken Lucas, who previously held the seat and is mounting a comeback. One piece says Lucas "puts illegal immigrants before American taxpayers," while Davis "puts Americans first."

A similar piece by the NRCC said Democrat Tammy Duckworth, an Army National Guard veteran who lost both her legs in the Iraq War and is now seeking an open seat in Illinois, "opposes securing the border right now" and " won't stop illegal aliens."

Who will benefit from all the negativity this time remains to be seen. There is an anti-incumbent mood this year, but that gets confused when both candidates are seen as unpalatable, analysts say. "No matter how bad the environment is and no matter how disenchanted the voter is with the status quo," said one GOP strategist, "if the alternative candidate is seen as less palatable than the incumbent, the incumbent wins."