So Obama wades back into the inequality debate today with a speech in Anacostia. He's been gunshy about this subject over these last five years. He'll give the occasional big speech, like the one in Kansas two years ago, and then he'll just sort of drop it.

Why? I see some combination of three reasons. It makes Wall Street jittery, this talk, and he seems pretty jittery about making Wall Street jittery, because the instant he does they start whining about being made into pariahs. Second, one can't help but suspect that race plays a factor here; he may fear that talking about inequality and poverty, as a black man, would sound to white middle America "too black," so to speak.

And third, there remains in the Democratic Party this intra-party fight about economic populism and growth. What used to be called, and I guess can still be called for want of anything better, the Rubin Wing of the party (the Third Way Wing?) wants the Democrats to play ball on entitlement cuts and deficit reduction, while what can already be called the Warren Wing, even though she's a pretty junior senator, but such is her outsized influence, wants more dramatic efforts in behalf of mobility for the middle class and the poor, which requires public investment that does not cut the deficit.

Talking about poverty, alas, doesn't pay many political dividends. But I don't see how it's a political loser to emphasize mobility. In a big poll that came out in September, more than half of those surveyed said they didn't think they'd move up the social ladder in their lifetimes. Not the usual American optimism. That has to include a lot of white people--indeed, a lot of white people who vote Republican because of social issues. Some portion of them could be won back by Democrats if those voters really feel the Democrats are on their side economically.

Obama isn't going to win them back, and anyway he's not facing voters again. But Hillary Clinton, with her husband's help, could win some of them back. The most successful portion of her 2008 campaign was the part where she tacked to the economic left for the Ohio and Pennsylvania primaries. One of the most interesting questions about a Clinton 2016 effort, should she undertake it, will be about what kind of economic platform she lays out, whether more Rubinesque (which has certainly been her comfort zone most of her career) or more Warrenesque.

Or can she accomplish some kind of synthesis? That's the brass ring. The trick, I think, is to show the overclass that they too will benefit from investments in the middle class and in social mobility. They always have in the past. Clinton, with her Rubinesque history, can be the credible vessel to take that message to Wall Street.

In the meantime, Obama should be highlighting mobility nonstop from here to 2017. He won't get anything through Congress, and that's obviously unfortunate for the working people who might be helped by legislative initiatives along these lines. But he can point a direction for the party, and he shouldn't care what Republicans say. They don't represent moderate middle America. They represent right-wing America. He shouldn't worry about what they say.