Going into Tuesday's primaries, the question of race and the racial divide in the Democratic electorate weighed heavily on observers' minds, as it always seems to lately.

Well, no surprise, it turns out that Democratic voters are still divided along racial lines, and that divide seems to have played a role in the night's results.

In Indiana, the electorate was 81 percent white, 15 percent African-American, 2 percent Latino, 1 percent Asian and 2 percent other. (The only numbers for candidate preference that we have from exit polling are for whites and African-Americans, however -- the same is true of North Carolina.) Whites went for Hillary Clinton, 60-40. African-Americans voted overwhelmingly for Barack Obama, 92-8.

Exit poll respondents in Indiana were also asked whether the race of the candidate was important. Fifteen percent said it was -- they broke for Clinton, 57-43. The 84 percent who said it was not important also went for Clinton, but by a smaller margin, 51-49.

In North Carolina, the percentage of voters who are African-American was much larger. That was expected -- in many Southern states where party identification is polarized along racial lines, African-Americans make up a substantial and critical portion of Democratic voters. Sixty-two percent of voters in North Carolina's Democratic primary were white; they went for Clinton, 60-40. Thirty-three percent of the electorate were African-American; they went for Obama, 91-6.

North Carolina voters were also asked whether race had been important to them. Seventeen percent said yes. Obama won that group, 62-34. Eighty-one percent said no; Obama won that group as well, but by 54-42.