In the annals of improbable explanations, Bob Johnson's ranks right there at the top. Introducing Hillary Clinton at a campaign event in South Carolina Sunday, Johnson, the founder of Black Entertainment Television, said that the Clintons were "deeply and emotionally involved in black issues" when Barack Obama was still "doing something in the neighborhood, that I won't say what he was doing, but he said it in his book."

Another not-so-veiled reference to Obama's admissions of past drug use? In a statement released Sunday afternoon, Johnson said it would be "simply irresponsible and incorrect" to read his words that way. "My comments today were referring to Barack Obama's time spent as a community organizer, and nothing else," he insisted.

As Walter Shapiro notes today in Salon, Johnson's explanation is "giggle"-inducing. But maybe it's a little worse than that. Johnson's explanation came via an e-mail message distributed by the Clinton campaign's press office, which certainly suggests some kind of stamp of approval for a claim that's so obviously false. And this morning, Johnson's statement got a semi-explicit endorsement from Bill Clinton himself. Asked about Johnson's explanation in a radio interview, the former president said: "I think we have to take him at his word."

Clinton said that "nobody knew" what Johnson was going to say Sunday, and he insisted that it "wasn't part of any planned strategy." If that sounds familiar, maybe it's because it is. When Clinton's New Hampshire co-chair raised the issue of Obama's past drug use as a barrier to his electability last month, a Clinton campaign spokeswoman said the remarks "were not authorized or condoned by the campaign in any way." And when Clinton strategist Mark Penn went out of his way to mention Obama's "cocaine" use on "Hardball" last month, he said that "the issue related to cocaine use is not something that the campaign was in any way raising."

Then, as now, we'll just have to take him at his word.