Concepts familiar from grade-school algebra have broad ramifications in computer science.
Some political observers have declared that the election of the first black president signals a new era of post-racial politics in the United States -- but the data show otherwise, two MIT researchers say.
Through careful analysis of 2008 exit-poll data, the researchers found that Barack Obama won the election precisely because of his race, most significantly because of his appeal among black voters who turned out in record numbers.
"Ironically, the candidate whom commentators lionized for ending America's debilitating racial divisions won the election on the basis of increasingly distinct white and nonwhite voting patterns," wrote the two researchers -- Charles H. Stewart III, the Kenan Sahin Distinguished Professor and head of the Department of Political Science at MIT; and Stephen Ansolabehere, professor of political science at MIT -- in the current issue of Boston Review. "Racial polarization in American voting patterns was the highest it has been since the 1984 election."
Despite many predictions, Obama did not "provoke a backlash among white voters," according to research compiled by Stewart and Ansolabehere. However, the percentage of blacks voting Democratic rose from 88 percent in 2004 to 95 percent in 2008. Hispanic voters -- who had been drifting into the Republican camp in recent years -- heavily favored Obama; Hispanics voting Democratic rose from 56 percent to 67 percent. "This additional support among nonwhites proved decisive," Stewart and Ansolabehere concluded.
Indeed, "had blacks and Hispanics voted Democratic in 2008 at the rates they had in 2004, McCain would have won," they wrote.
This is not to say that Democrats lost ground among white voters; the Democrats did gain white votes but only a modest 3 million. "John McCain, on the other hand, received 2.3 million fewer votes than did George W. Bush in 2004. Most of this loss, 1.5 million votes, came from the net defection of blacks and Hispanics who voted Republican four years earlier; by comparison he lost 'only' 1.4 million white voters. Thus, Obama gained not only by bringing new minority voters into the electorate, but also by converting minority voters who had previously been in the GOP stable," the researchers wrote.
The "youth" vote has been touted as a deciding factor in Obama's favor and while those under 30 voted overwhelmingly Democratic, youth turnout was only 18 percent of the total -- nowhere near the highs of 1972 and 1992. Thus, it had virtually no impact on Obama's victory, Stewart said in an interview.
Of greater significance were voting patterns of the "older young," those aged 25 to 30, Stewart said. This group was strongly for Obama and is likely to remain Democratic eight years from now even as they gain in social and economic power. Like the generation of Reagan Republicans before them, Obama Democrats could impact elections for decades, Stewart said.
The shift in Hispanic voting patterns is also significant. Hewing to anti-immigration positions, Republicans largely turned off Hispanic voters, Stewart said. Not only does that make it unlikely that these voters will "turn back" to Republicans, but the Hispanic population is growing -- a boon to Democrats although Hispanics are not as "monolithically Democratic as African-American voters," Stewart said.
Stewart noted that current research is preliminary; as more exit-polling data is released, MIT researchers will be able to get a better idea of why populations voted in certain patterns and the possible effect of other factors, such as vice-presidential picks.
While some may fairly argue "that the fact that whites did not run away from Obama is evidence of post-racial politics," post-election commentators went overboard in suggesting "race doesn't matter in American politics," Stewart said.
Given white voting patterns, Republicans may even be tempted to return to racial politics to drive a wedge between white votes and the Democratic party, Stewart noted. He doubts that will happen.
"Watching how whites respond to Obama will be very critical to both Obama's future prospects and the nature of future campaigns," he said. "I don't think we're out of the woods yet in respect to seeing things like Willie Horton ads."
A version of this article appeared in MIT Tech Talk on February 4, 2009 (download PDF).