It was as low a blow as has lately been landed in national politics.

And it had all the subtlety of a surprise kick to the groin.

Bill Shaheen, husband of ex-Gov. Jeanne Shaheen of New Hampshire, a national co-chair of the Clinton campaign, volunteered to The Washington Post his concern at what might happen to Barack Obama, were he to be nominated.

"The Republicans are not going to give up without a fight, and one of the things they're certainly going to jump on is drug use," said Shaheen. And, as Obama has admitted in his autobiography to using drugs, this will "open the door" to further probing.

"It'll be: 'When was the last time? Did you ever give drugs to anyone? Did you sell them to anyone?' There are so many openings for Republican dirty tricks. It's hard to overcome."

Well, it's sure going to be harder to overcome, now that Bill Shaheen has suggested young Barack might have been a drug-dealer on the South Side of Chicago, and now that the press has been alerted as to precisely what questions should be put to him -- before Iowa.

Having planted this poisonous weed, Shaheen dutifully resigned. Then Mark Penn, Hillary's top adviser, went on "Hardball" to assure us his campaign would not stoop so low as to raise the issue. Said Penn, "I think we have made clear that ... the issue related to cocaine use is not something that the campaign was in any way raising."

By introducing cocaine, Penn alerted the press that, if Obama did deal drugs, we are not talking airplane glue or mushrooms. This little episode validates Robert Novak's report a month ago, when, relying on a Clinton source among other Democrats, Novak wrote:

"Agents of Sen. Hillary Clinton are spreading the word in Democratic circles that she has scandalous information about her principal opponent for the party's presidential nomination, Sen. Barack Obama, but has decided not to use it. The nature of the alleged scandal was not disclosed.

"This word-of-mouth among Democrats makes Obama look vulnerable and Clinton look prudent. It comes during a dip for the front-running Clinton after she refused to take a stand on New York Gov. Eliot Spitzer's now discarded plan to give driver's licenses to illegal aliens."

Putting it all together, it would appear that:

A) The Clinton campaign has acquired and been sitting on information about Obama's past involvement with drugs.

B) The Clintonites initially decided not to use it, but to leak word they had it. This would shake Obama up and knock him off his game. Continued...