Sen. Barack Obama has been roundly criticized in the media for both his association with the Rev. Jeremiah Wright and his handling of the controversy.

Will Obama's changing positions hurt him assuming he wins the Democratic nomination, which is still likely? Or does his most recent repudiation of the minister provide a new opportunity?

Obama is not the first presidential candidate to face such a political crisis that might derail a campaign. But if recent history is a guide, most of these dust-ups involving associates are eventually forgotten once the media moves on to the next revelation.

However, during the 2000 contest, Al Gore's campaign was dogged by revelations and repercussions from numerous scandals dating back to questionable fund-raising from Buddhist monks during the 1996 Clinton-Gore re-election campaign in which his version of events evolved repeatedly.

In an echo of the scandal, Sen. Hillary Rodham Clinton's dealings with disgraced Democratic fundraiser Norman Hsu resulted last fall in her giving back $850,000 and apologizing. In February, Sen. John McCain flatly denied a New York Times report that insinuated the presumptive GOP nominee had an inappropriate relationship with a female lobbyist. Both Clinton and McCain flaps have largely dissipated. However, both are no strangers to controversies played out in the media spotlight: Clinton can reflect on the damage control necessary in the wake of her husband's relationship with an infamous former White House intern, while McCain successfully defended himself in the Keating Five brouhaha.