It's taken a few days to find the time to crunch these numbers, but it appears as if Barack Obama's political boasts of earlier this week won't amount to much change in the electorate, even if he achieves his goals.Obama said:

"I guarantee you African-American turnout, if I'm the nominee, goes up 30 percent around the country, minimum."

Obama noted that in Mississippi, blacks make up more than a third of the state's population, but make up a smaller share of the electorate.

"If we just got African-Americans in Mississippi to vote their percentage of the population, Mississippi is suddenly a Democratic state," Obama said. He said Georgia would also turn Democratic and South Carolina would be in play.

According to a back-of-the-envelope calculation by this non-math major, if black voters voted their percentage of the population, Democrats would still be about 170,000 votes short of the regular Republican general election margin, all other factors held constant.

Same thing in Georgia: the Dems would be 325K votes short and in South Carolina -- well, the Dem tally would decline because African Americans vote more than their percentage of the population would indicate.

So -- the first column shows the Bush margin over Kerry in '04. The second shows the total number of Democratic voters if black voters voted their percentage and all voted Democratic. The third figure is the difference of the first minus the second -- the GOP margin over the Democratic candidate under these conditions...all other things being equal.

         BUSH MARGIN     CHANGE IF PERCENT      GOP WITH CHANGE
Georgia    548K                 223K                           324K      
Mississ.   226K                   53K                           173K
S.C:    276K                  -16.9K                           293K

Sources for this were the percentage of African Americans per state from the U.S. Census and the '04 exit polls' estimates for the percentage of African American votes in the election. . Now -- increasing African American turnout in other states may well yield benefits. But remember that Democratic get-out-the-vote efforts have, in past cycles, almost entirely been focused on squeezing every possible African American vote out of a state.

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