The comparison Obama will hear about again: "The worst thing of all, that I think really indicates Senator Obama's attitude, is he had the incredible statement that he compared Mr. Ayers, an unrepentant terrorist, with Sen. Tom Coburn, Sen. Coburn, a physician who goes to Oklahoma on the weekends and brings babies into life."
And asked whether it was a mistake to seek the endorsement of the Rev. John Hagee, McCain responded: "Oh, probably, sure."
It's "the latest indication that the general election campaign is likely to see a heavy dose of cultural politics," Juliet Eilperin writes in The Washington Post.
Said Obama spokesman Bill Burton: "Unable to sell his out-of-touch ideas on the economy and Iraq, John McCain has stooped to the same smear politics and low road that he denounced in 2000."
McCain won't be the last to go there -- and denizens of Obamaland know it. "The Obama campaign is planning to expand its research and rapid-response team in order to repel attacks it anticipates over his ties to 1960s radical Bill Ayers, indicted developer Antoin Rezko and other figures from his past," Newsweek's Mark Hosenball and Michael Isikoff report.
"The move appears to be an acknowledgment that the Obama campaign may not have moved aggressively enough when questions about Ayers and Rezko first arose, and it comes amid fresh indications that conservative groups are preparing a wave of attack ads over the links."
Democrats are worrying about what they're learning about Obama, too. ABC's Kate Snow reports that labor leader Rick Sloan has written a memo to fellow Democrats: "Titled 'What Is Rove Up To?,' Sloan writes that [Karl] Rove will seek to redefine Obama's signature slogan 'Change We Can Believe In' and brand it instead as 'revolutionary change, change driven by an alien ideology, change no patriotic American could stomach. And he intends to do so by channeling Sen. Joseph McCarthy.' "
Said Sloan: "Democratic operatives ought to be aware of what the Republican attack machine has been doing for two weeks."
How does it end? The worsening tone is "stoking more worries among Democrats that the party's eventual nominee will head into the general election badly damaged," Jackie Calmes writes in The Wall Street Journal. "But no single leader or clique exists within the fractious party to end the fight, and those with influence insist voters must have their say."
"Nevertheless, some party leaders are quietly planning to try to end the clash, said people familiar with the matter," Calmes reports. "After the primaries end in June, these influential Democrats -- led by House Speaker Nancy Pelosi -- plan to push the last uncommitted party leaders to endorse a candidate, in hopes of preventing a fight at the August presidential convention, party insiders say."
Donna Brazile looks ahead: "There's a group around [Sen. Clinton] that really wants to take the fight to the convention. They don't care about the party. It scares me, and that's what scares a lot of superdelegates."