By The Numbers

In the aftermath of Barack Obama's speech on race -- and the followup interview in which he referred to his white grandmother as a "typical white person" -- it may be helpful to review some of the numbers.

First of all, the thing that is of the most immediate interest to political observers is how things are shaping up in Pennsylvania, site of the next presidential primary on April 22.

According to a Public Policy Polling survey, which was completed a couple of days before Obama's speech, Hillary Clinton was leading Obama in Pennsylvania, 56% to 30%.

The margin was closer in a poll conducted jointly by Franklin & Marshall College/Philadelphia Daily News/WGAL TV/Pittsburgh Tribune Review/WTAE TV/Times Shamrock Newspapers, which was also completed a couple of days before the speech, but Clinton was the leader in that one as well, 51% to 35%.

Quinnipiac University reported an even closer margin, 53% to 41% -- still in Clinton's favor. Once again, that survey was completed before Obama's speech.

I have found no survey results from polls that were conducted after the speech or the interview -- yet. We'll probably start seeing those numbers this week.

To put things into a more appropriate context, Pennsylvania's racial makeup is about 84% white, just under 10% black.

That racial deficit didn't necessarily work against Obama in previous primaries -- but all of the previous primaries were held before the airing of clips of his pastor's hate-filled remarks, Obama's speech or his followup interview. One can only speculate about what sort of impact they might have had on earlier contests.

On average, Clinton has been receiving 53% of white votes, Obama has been receiving 39%.

In case you're interested, Obama also has been losing the Hispanic vote to Clinton in most states, 58% to 39%. Hispanics are the fastest-growing ethnic group in America, but Hispanics historically do not vote in large numbers, even in places where they represent a fairly large portion of the population. Many have been participating in the primaries this year, but it remains to be seen if that activism continues into the general election.

In some of the states with larger ethnic populations (i.e., California), Obama has more than made up for lost white votes by receiving huge majorities among black voters. His advantage among black voters has been consistently high, 80% to 17% on average.

But if he starts losing white votes by the same margin -- or close to it -- with which he has been winning black votes, the simple math suggests that his campaign could be in trouble.

We've been hearing for weeks that the only way Clinton can capture the nomination is to start winning primaries with the support of more than two-thirds of the voters.

We're about a month away from the Pennsylvania primary. In that time, Obama has to assess the damage that's been done to his image in the white community and find a way to correct it.

If he succeeds, the nomination will be his for the taking. But that doesn't necessarily mean he will win the general election.