Jon Alter has some scoop:

Prominent Democrats are upset with the aggressive role that Bill Clinton is playing in the 2008 campaign, a role they believe is inappropriate for a former president and the titular head of the Democratic Party. In recent weeks, Sen. Edward Kennedy and Rep. Rahm Emanuel, both currently neutral in the Democratic contest, have told their old friend heatedly on the phone that he needs to change his tone and stop attacking Sen. Barack Obama, according to two sources familiar with the conversations who asked for anonymity because of their sensitive nature. [snip]

"This is excruciating," says a member of the Clintons' circle, who asked for anonymity. "But the stakes couldn't be higher. It's worth it to tarnish himself a bit now to win the presidency."

Why does that last quote not surprise me?

On primary day in New Hampshire a couple of weeks ago, I wondered how this fight would shake out:

How ironic is it that Bill Clinton - once dubbed America's first black president - is now in the position, along with his wife, of having to go negative against a black man who appears to have the first legitimate chance of winning the White House? If the Clintons are successful in snuffing out Obama's insurgency with swift boat like tactics, how much venom and hatred will that unleash against them by progressive activists and the African-American community - and how might that play a role in the general election?

Bill may indeed back off, now that his wife has regained the upper hand with a win yesterday and the Democratic race shifts to South Carolina. If Obama wins convincingly there, however, don't be surprised to see Bill back on the attack heading into February 5th.