When Rupert Murdoch first announced his intention to buy the Wall Street Journal, the reaction from Washington was muted, to say the least.

Now that the News Corp. kingpin's takeover of Dow Jones is imminent, a few brave politicians have raised questions about whether one company - and one man - should control so much of the media.

Two leading presidential candidates already have jumped into the fray. Former North Carolina Sen. John Edwards challenged his fellow candidates to take on media consolidation:

News Corp's purchase of the Dow Jones Co. and the Wall Street Journal should be the last straw when it comes to media consolidation. The basis of a strong democracy begins and ends with a strong, unbiased and fair media -- all qualities which are pretty hard to subscribe to Fox News and News Corp. The reality is that Americans deserve more news outlets -- not fewer. It's time for all Democrats, including those running for president, to stand up and speak out against this merger and other forms of media consolidation.

Connecticut Sen. Chris Dodd was the first candidate to sound the alarm about the deal's devastating impact on quality journalism at the financial paper of record:

The power of the media is swiftly being limited to a few controlling hands, which poses a serious threat to our democracy. ... I am concerned that it will be very difficult for the Journal to offer fair and balanced reporting under the pressures of a giant-media conglomerate.

So far, the rest of the presidential field -- Democrats and Republicans -- has been silent about Murdoch's Journal bid. But with seven of the Democratic candidates in Chicago today for the YearlyKos Convention, now's the perfect moment to show a united front against runaway consolidation and the "Fox Effect" on the news.

We're especially eager to hear from Sen. Hillary Clinton - who was feted by Murdoch at a campaign fundraiser in May 2006 -- on how her administration would stand up to the media conglomerates. Meanwhile, in Washington, pressure is increasing on the Federal Communications Commission not to rubber-stamp this deal.

In a sharply worded letter sent to FCC Chairman Kevin Martin on Friday, Sen. Byron Dorgan (D-N.D.) suggested we may need new rules to rein in national media concentration:

The proposed merger between News Corp. and Dow Jones raises the serious question of whether a single company's concentration on a national scale should continue to be unfettered and unchecked. I believe the FCC should consider studying whether the public interest would be served if media cross-ownership rules existed at the national level.

FCC Commissioner Michael Copps is already on the record urging his colleagues not to abandon their responsibility to protect the public interest:

What's good for shareholders of huge media conglomerates isn't always what's good for the public interest or our civic dialogue. We should immediately conduct a careful factual and legal analysis of the transaction to determine how it implicates specific FCC rules and our overarching statutory obligation to protect the public interest. I hope nobody views this as a slam-dunk.

Given the power big media exerts over the election process -- through both its campaign coverage and pipeline for political advertising -- it's not surprising that most candidates have kept quiet. But it's time more politicians found their backbone on this issue.

-- coauthored with Craig Aaron