ROY BLUNT ABANDONS SHAME, TRIES TO EXPLOIT 9/11 FOR PARTISAN GAIN…. Missouri is home to a competitive Senate race this year, so it stands to reason that the frontrunner, ethically-challenged Rep. Roy Blunt (R), is going to go all out in attacking Secretary of State Robin Carnahan (D).

But there are at least some lines of decency that candidates shouldn’t cross if they expect voters to respect their character. The Blunt campaign seems to have forgotten this.

Blunt’s Republican team posted a web video yesterday, featuring an image of Ground Zero shortly after the 9/11 attacks nine years ago — with visible smoke still rising the devastation. It’s still a painful image, and it’s precisely the kind of visual that have no place in some politician’s attack ad.

Roy Blunt, however, added an audio track to the image, playing his opponent’s recent answer to a question about Park51 over the visual. “Look, I’m not going to try to tell folks in New York what to do — and I don’t want them trying tell us in Missouri what to do — so in the end, it’s going to have to be their decision,” Carnahan is heard saying. “But I think this is a time where we ought to be trying to get people of all faiths to come together, not divide them.”

And that’s it. It’s the whole clip — nothing more than the 9/11 photo shown over Carnahan’s response. Why Blunt considers her remarks so scandalous is a mystery — it’s a local decision, and now’s a good time to try to bring people together — but I have trouble relating to right-wing thinking anyway.

Regardless, the campaign video is, quite literally, disgusting.

The Carnahan campaign has called on Blunt to apologize, not to his opponent, but “to the families of the 9/11 victims, whose tragedy he exploited for his own personal political benefit.”

Blunt’s campaign pulled the video this morning, saying it “didn’t reflect the right tone.” But as Greg Sargent noted, “Interestingly, even though the Blunt campaign has yanked the video showing the 9/11 wreckage, the audio of Carnahan talking about Cordoba House is still front and center on Blunt’s Web site.”

And in case you were curious, Blunt was “one of 155 Republicans to vote [last month] against a benefits bill for emergency workers who responded to the 9/11 attacks.”

It’s tempting a story like this will do real damage to Blunt’s campaign — Missouri may be a “red” state, but it still tends to take integrity and decency seriously — but time will tell.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.