It looks like some of Hillary's prominent black endorsers (who double as superdelegates) are starting to have serious second-thoughts about supporting her. Here's what the AP is reporting this evening:

In a fresh sign of trouble for Hillary Rodham Clinton, one of the former first lady's congressional black supporters intends to vote for Barack Obama at the Democratic National Convention, and a second, more prominent lawmaker is openly discussing a possible switch.

Rep. David Scott's defection and Rep. John Lewis' remarks highlight one of the challenges confronting Clinton in a campaign that pits a black man against a woman for a nomination that historically has been the exclusive property of white men.

"You've got to represent the wishes of your constituency," Scott said in an interview Wednesday in the Capitol. "My proper position would be to vote the wishes of my constituents." The third-term lawmaker represents a district that gave more than 80 percent of its vote to Obama in the Feb. 5 Georgia primary.

Lewis, whose Atlanta-area district voted 3-to-1 for Obama, said he is not ready to abandon his backing for the former first lady. But several associates said the nationally known civil rights figure has become increasingly torn about his early endorsement of Clinton. They spoke on condition of anonymity, citing private conversations.

In an interview, Lewis likened Obama to Robert F. Kennedy in his ability to generate campaign excitement, and left open the possibility he might swing behind the Illinois senator. "It could (happen). There's no question about it. It could happen with a lot of people ... we can count and we see the clock," he said.

This won't come as a surprise to readers of our current issue. As I reported in my piece this week, many of Scott's constituents had been frustrated with his support for Hillary, and there was talk of it earning him a primary challenger:

[A]ccording to an Atlanta-based political strategist who works in the African American community, Representative David Scott could face more serious problems in Georgia, where Obama won nearly 90 percent of the black vote. "There are definitely rumblings among young people," says the strategist. "[The Hillary endorsement] was a lot riskier for Congressman Scott." Complicating the situation is the fact that there are now at least three formidable African American politicians raising money for what's expected to be an intensely competitive Atlanta mayor's race in 2009. At least two of those candidates will lose, leaving them with an organization, a fund-raising network, and an itch for higher office. It wouldn't be shocking if one of them challenged Scott.

The piece mentions a few other African American endorsers/superdelegates who are also strong candidates for a change of heart.

--Noam Scheiber