As my colleague Rick Green reports, Senate candidate Chris Murphy is calling on television stations to stop running an ad from opponent Susan Bysiewicz that incorrectly claims Murphy is the biggest recipient of hedge fund cash among Democrats in Congress.

The Bysiewicz campaign has acknowledged the error but said it would keep the spot running, prompting Murphy’s lawyers to take to their word processors and lean on local stations to yank the ad. That’s not likely to happen, because misleading or not, broadcasters are generally required by law to run candidate ads exactly as they get them.

The letter from Murphy’s lawyers cites – as these sorts of cease-and-desist letters frequently do – a 1961 Federal Communications Commission ruling that broadcast stations have a duty “to protect the public from false, misleading or deceptive advertising.” What the letter leaves out is that that duty is limited to commercial advertising – not political advertising.

When it comes to political ads – at least political ads directly from bona fide federal candidates – station’s are generally prohibited from censoring or refusing the spots, no matter how off-the-wall they may be. In those cases, the FCC takes the position that the marketplace of ideas – not federal bureaucrats – are the best defense against false ads.

In other words: There’s not much Murphy can do to get the spots pulled off the airwaves. But he is free to do all he can to hammer his opponent for the inaccuracy; like, for instance, sending letters from his lawyers to the stations – and the media – pointing out once again that the ad was wrong.