Tough call for righties, as it pits two core conservative experiences against each other — false accusations of racism by the left for political advantage and faith in the fact that there are no depths to which the Clintons will not sink. Ace calls this a taste of what Republicans will be getting by the barge-load if Obama’s the nominee, but that’s not quite true. In the general election the media will do all this work for him. In the primary, in a contest of people of Pure Heart, his campaign’s got to nudge them along. See, for example, this comically anguished semi-apology from Josh Marshall to his readers for even covering the racial angles, urging them to exercise caution in jumping to conclusions about ill intent and command and control. This is the same guy, you’ll recall, whose outfit gleefully accused the GOP of racism last year for running an ad targeting Harold Ford that dared to feature timpani — drums — in the background.

Like Ace says, by the standards of the party’s own cretinous identity politics, who the eventual nominee is will determine whether the left still has more of a racism problem than a sexism problem or vice versa. That applies to certain subgroups within the left, too. Look who’s shaping up to be a key bloc:

Obama has never made his race central to his campaign. That’s about to change, as Nevada, with its large Hispanic population, and South Carolina, with its large black population, prepare to vote. Obama has an interest in downplaying his race in both states. There are lingering tensions between the Hispanic and black communities which he doesn’t want to inflame, and some residual skepticism among black voters concerning Obama’s electability among whites…

On the morning after Clinton’s victory, I talked to Sergio Bendixen, one of her pollsters, who specializes in the Hispanic vote. “In all honesty, the Hispanic vote is extremely important to the Clinton campaign, and the polls have shown—and today is not a great day to cite polls—that even though she was slipping with women in Iowa and blacks in South Carolina, she was not slipping with Hispanics,” he said. “The fire wall doesn’t apply now, because she is in good shape, but before last night the Hispanic vote was going to be the most important part of her fire wall on February 5th.” The implications of that strategy are not necessarily uplifting.

When I asked Bendixen about the source of Clinton’s strength in the Hispanic community, he mentioned her support for health care, and Hispanic voters’ affinity for the Clinton era. “It’s one group where going back to the past really works,” he said. “All you need to say in focus groups is ‘Let’s go back to the nineties.’ ” But he was also frank about the fact that the Clintons, long beloved in the black community, are now dependent on a less edifying political dynamic: “The Hispanic voter—and I want to say this very carefully—has not shown a lot of willingness or affinity to support black candidates.”

Which, of course, explains her latest twist on gender appeals. So there’s your next Chris Matthews Unified Field Theory of how Hillary won. Even so, my sympathies in all this lie slightly with her thus far, notwithstanding the occasional contemptible belittling crack from (somewhere within) her camp, just because Billy Jeff’s “fairy tale” comment has been so distorted that it’s hard to believe the Obama camp’s not spinning in bad faith. Too bad; he really had run an admirably post-racial campaign thus far. The politics of hope and transcendence look good when you’re 10 points up in New Hampshire and on the brink of a trot to the nomination, but after an upset, with a huge black vote up for grabs in South Carolina, I guess it’s hard to resist division and demagoguery. Inevitable, too: One of the requisites of identity politics is defending “your” group when it’s attacked to prove yourself their champion and cement the sense of identification. Hence the memo, and hence Hillary’s savvy jab about the remnants of sexism when those idiots broke out the “Iron My Shirt” sign.

None of which is to suggest that he isn’t being falsely accused on this score by her team, too. Or that he’s even half as cynical a campaigner as she is.