On Aug. 23, 2008, Jacob Weisberg of Slate decried what was then a dead heat in the presidential campaign. Barack Obama was so plainly better than John McCain, Weisberg argued, that only white racism could explain the polls. “Much evidence points to racial prejudice as a factor that could be large enough to cost Obama the election,” Weisberg wrote.

Today, President Obama is running for reelection, but pundits are again attributing his inability to put away a lackluster GOP opponent to the racial animus of white voters.

Are the claims convincing?

Yes and no. To some extent race, and racism, will affect the 2012 election, as they have all previous elections. They have always been part of American life and, therefore, part of American politics.

The two parties were polarized along racial lines before Obama’s rise, with the Republicans getting about six out of 10 white votes in most presidential elections since 1980 and the Democrats getting nine out of 10 black votes. Racially coded attacks on Obama, from the blatant — the “birther” canard — to the subtle have not eased that polarization.

But tremendous racial progress is a reality, too, as Obama’s election confirms. It’s one thing to acknowledge that race will be a factor in November — and quite another to say that it will be decisive.

Michael Tesler of Brown University has used regression analysis of survey data to show that racial resentment made Obama less popular among whites in the 2008 general election than a white Democrat with similar left-of-center views would have been. According to Tesler, the same tendency applies to whites’ view of Obama’s policies in office, such as health care.

At the same time Obama lost some whites’ backing, however, he got higher support among liberal whites and blacks than an ideologically similar white would have, Tesler found.

The “pro” and “anti” responses are not morally equivalent. There were benign reasons to favor Obama because of his race — e.g., a desire to help “make history” — but not to judge him more harshly.

Yet they are politically equivalent: According to Tesler, the two effects roughly canceled each other out in terms of votes, with perhaps a slight penalty for Obama. His race deepened the electorate’s polarization but did not alter the 2008 outcome. Obama got 53 percent of the popular vote, the best performance for any Democrat since 1964.

Even if white racial resentment did cost Obama votes in the general election, Tesler’s research implies a sense in which his race nevertheless helped him win the presidency. Extra support from liberal whites and blacks buoyed him in the battle against Hillary Clinton for the Democratic nomination — and without the nomination, of course, Obama never would have gotten a shot at McCain.

Today, Obama is running on his record, not his promise. It would be hard for anyone to get reelected in this economy, which is why the dead heat between Obama and Republican Mitt Romney is well within the range of potential outcomes predicted by political-science models, for whatever they’re worth.

What’s striking — to me, at least — is the degree to which the public prefers Obama as a person to Romney. Most whites express admiration for his intellect and character — not what you’d expect racists to say.

The Pew Research Center’s January 2012 survey found that large majorities of non-Hispanic whites call Obama a “good communicator,” someone who “stands up for his beliefs,” “warm and friendly,” “well-informed,” “trustworthy” and someone who “cares about people like me.” Whites’ views are less favorable now than they were when Obama took office, but they declined at the same rate as everyone else’s.

Obama lost whites’ approval on only two job-related indicators: “strong leader” and “able to get things done.”

Maybe this is why Romney shifted to a more-in-sorrow-than-anger tone when talking about Obama at the GOP convention.

Romney himself belongs to an oft-despised minority. From the mid-1960s until today, Gallup polling has consistently found that about a fifth of Americans would not vote for their own party’s presidential candidate if he or she were Mormon. In contrast, only 5 percent now say they would refuse to vote for an African American.

The link, if any, between anti-Mormon sentiment and Romney’s poor “likability” ratings has received little study. It is one more variable — along with the unemployment rate, debate performances and international events — that serious analysts will consider before drawing any conclusions about the degree to which the 2012 outcome hinges on President Obama’s race.