Our colleagues at Gannett News Service report that Biden also said today that Obama is "probably the most exciting candidate that the Democratic or Republican parties have produced" in a long time. Biden said his remark about Biden being "clean" reflected his mother's expression: "Clean as a whistle, sharp as a tack."
"I really regret that some have taken totally out of context my use of the word 'clean' " Biden said.
GNS also writes that Obama didn't take the comments personally and would not comment further, his Senate spokesman, Tommy Vietor, said in an e-mail response to a reporter's inquiry.
http://blogs.usatoday.com/ondeadline/2007/01/biden_on_obama_.htmlClean as a whistle:
be as clean as a whistle - if someone is as clean as a whistle, they are not involved in anything illegal. He hasn't got a criminal record - he's clean as a whistle. http://idioms.thefreedictionary.com/clean+as+a+whistle