Billy Shaheen, a national and New Hampshire co-chair for the Hillary Clinton campaign, says he's sorry that he raised questions Wednesday about Barack Obama's past drug use, and he insists that the Clinton campaign had nothing to do with it.

"I deeply regret the comments I made today," Shaheen said Wednesday night, "and they were not authorized by the campaign in any way."

The apology came in a statement issued by the Clinton campaign.

We're told that the campaign is genuinely unhappy that Shaheen used an interview with the Washington Post Wednesday to suggest that Obama's past drug use would be a problem for Democrats in the general election.

We don't doubt that. Shaheen's comments have provided the Obama campaign ammunition to argue that the Clinton team is going for the gutter in a desperate attempt to get through Iowa and New Hampshire, and the Clinton campaign -- which has painted itself the victim of unfair attacks -- now finds itself fighting a defensive battle on the "politics of hope" front.

That said, even if it wishes that the drug-use comments hadn't been made by a campaign co-chair whose "guidance and leadership" Clinton has publicly embraced, the campaign can't be too unhappy that voters in New Hampshire have been reminded of Obama's past drug use. High-minded debates over healthcare plans and Iran are great. But if you were running for office in a tight race, would it bother you so much if voters were talking over dinner about your opponent's past use of marijuana and cocaine?

Whatever regrets Shaheen or the Clinton campaign may express, that genie is out of the bottle, to the extent that it was ever in one. Maybe now it's time for a truce. The Obama campaign can graciously accept the Clinton campaign's claim that it had nothing to do with Shaheen's remarks. In exchange, the Clinton campaign can stop beating up Obama -- as it has been for the last couple of days -- with a 1996 candidate questionnaire his campaign says he "never saw and never approved."