The Mississippi exits

The results of Mississippi's primary today show a sharp divide along racial lines, with overwhelming African-American support for Barack Obama, and a solid, though less sweeping, white majority for Hillary Clinton.

Though it may be tempting to link those results to the current, racially-charged moment of the primary, a more straightforward explanation is regional: That polarization has been consistent across the Deep South, though only Alabama has had results this starkly divided.

Voters rated the economy the top issue.

Obama won the support of 91% of African American voters -- who made up a far smaller share, 48%, than they did in the 2004 primary, when well over half of the voters were black. Clinton, meanwhile, won 72% of the state's white vote, which represented a slightly larger share of the overall Democratic electorate.

Those numbers come from early exit poll numbers are subject to minor revision.

Clinton won more narrowly -- by six percentage points -- among white independents, who made up 14% fo the total electorate, according to the exit polls.

Reversing a trend common in the north, Clinton was dominant among the Republicans who made up 11% of the voters in this primary. In fact, Republicans were here strongest single group, giving her 85% of their votes. Elsewhere, Republicans and independents have flocked to Obama's side.

Reversing another much-commented on trend visible in the March 4 primaries, a majority of voters who cited race as an important -- or the important -- factor in making their decisions sided with Obama.

Obama's delegate margin isn't yet clear, and keep an eye on Politico.com for the returns.