Does racism affect voters' responses to President Barack Obama's policies? In September, former president Jimmy Carter argued yes in an interview with Brian Williams of NBC. A Democracy Corps focus-group study published on Oct. 16 disagreed, concluding that racial issues do not affect voters' beliefs, and that it was time for those who think otherwise to "get over it."

Recent research from Stanford GSB finds that Carter is correct — race does matter. People's implicit racial prejudices corresponded with a reluctance to vote for Obama and with opposition to his health care reform plan, the study finds. In fact, when a description of a health care reform proposal was attributed to former President Bill Clinton rather than Obama, reactions suggested that individuals high in nonconscious antiblack prejudice tended to oppose Obama, at least in part because they dislike him as a black person.

"Many people are influenced by race, and either will not admit it or don't know it," says Brian Lowery, an associate professor of organizational behavior. To find evidence for "implicit," or nonconscious prejudice, he and two other investigators ran a computer-based test on more than 200 subjects prior to the 2008 presidential election. Individuals were asked to quickly pair "black" names (Aisha, Jamal, and so forth) and "white" names (Brett, Jane) with good words such as "beauty" and "friendly," or bad words such as "evil" and "hate."

Nonconscious prejudice was measured according to how quickly and easily people could identify the "bad" words after seeing African-American names (Aisha, Jamal, and so forth) as opposed to Anglo names (Brett, Jane). Lowery and his coauthors found that fewer errors, when African-American names (as opposed to Anglo names) were paired with a negative word, indicated that individuals had internalized negative associations with black people — and served as a measure of nonconscious prejudice.

In the month after the election, participants were asked how they had voted. Those who made few errors on the black/bad pairings were nearly 43% less likely to have voted for Obama than those with average scores. "As implicit prejudice increased, the likelihood of voting for Obama decreased," explains Lowery.

Nearly a year later, in October 2009, some of the same participants rated their attitudes about Obama's approach to health care reform. Others were randomly assigned to read a description of health care reform framed either as being President Obama's plan or Bill Clinton's plan.

Once again, increasing implicit prejudice was associated with negative attitudes toward Obama and decreasing support for his health care policy. Prejudice scores did not correlate with favorability toward the plan when it was described as coming from Clinton, but they did result in a more negative assessment when it was described as coming from Obama.

"This study represents a powerful demonstration of the fact that racial attitudes still operate in the political arena," says Lowery, who conducted the research with Stanford doctoral student Rebecca Schaumberg and Eric Knowles, assistant professor at the University of California at Irvine. "It also suggests that Obama is likely to encounter some degree of prejudice-fueled opposition to his policies across the board."

Clearly, the president has his work cut out for him.