The main spectacle in the presidential race today was the sight of Bill Clinton re-emerging with a vengeance as a major issue in the campaign.

After a months-long lull, during which Bill had reverted to a more supporting role in the campaign, he's suddenly back at the center of the action. Only this time, it's with a twist: Whereas in the runup to South Carolina the Hillary team was mostly fending off criticism of multiple Bill slip-ups, the Hillary campaign is now partly responsible for driving his re-emergence.

Hillary advisers are actively highlighting various criticisms of Bill by Obama surrogates in order to argue that Camp Obama is running a fiercely negative campaign that falls short of Obama's lofty promises of a new politics.

Bill has become an issue on two fronts today.

First, the Obama campaign broadened its criticism of Bill's Friday comments, which some described as an assault on Obama's patriotism, to hint that there's been a "pattern" of such assertions from the Clinton campaign. Hillary advisers hit back hard on the campaign's conference call by highlighting Obama supporter General McPeak's likening of Bill to Joe McCarthy, which Hillary spokesperson Phil Singer said is a sign that Obama now "firmly owns the low road."

Now there's been a Bill Eruption on another front, too. The Hillary campaign is also pointing to some unfortunate remarks by a key Iowa adviser to Obama, who described Bill's Friday comments as "a stain on his legacy" that's "much worse, much deeper, than the one on Monica's blue dress."

The adviser quickly apologized for the claims, but that didn't stop the Clinton camp from using them to tar the whole Obama campaign as ferociously negative and out of sync with Obama's lofty rhetoric. On the conference call, Hillary advisers repeatedly invoked the quote.

"There seems to be an insidious pattern of personal attacks," Singer said, adding that they weren't "in keeping with the high-minded rhetoric that certainly has helped fuel Obama's rise in our politics over the last 14 months or so." Singer added that the Obama camp was resorting to "gutter tactics."

That the Clinton camp would pursue a strategy that could renew attention on Bill seems striking, at least given what Hillary's own advisers were saying after the series of mistakes by Bill in the run-up to South Carolina. Some of them privately acknowledged that the focus on Bill had made it tougher for Hillary to portray her candidacy as historic and easier for Obama to cast the race as a choice between the "past and the future." (Polls were inconclusive on Bill's impact.) Bill himself toned down his role.

Given that background, the fact that the Hillary campaign is actively encouraging debate about these new episodes involving Bill suggests that Hillary advisers see tarnishing Obama's high-mindedness as so imperative that they'll grab any opportunity to do so and risk whatever potential downside they may see in refocusing the race on the former President.

It's a noteworthy development. We'll see where it goes.