Barack Obama looks ever more likely to take the Democratic nomination for President this year, having won every race since Super Tuesday, and with polls showing him closing the gap with Hillary Clinton in the upcoming races in Ohio and Texas. This raises the question: in a general election, will Americans vote for a black candidate to be the next President of the United States?

Polls done on this topic in recent years have shown that an overwhelming percentage of Americans (94% according to a recent Gallup Poll) are willing to vote for a black candidate. While this sounds encouraging, it is important to look at this number from another perspective. What percentage of Americans are willing to vote for a white, Protestant male? Though polls on this are unavailable, the implicit answer is close to 100%, since every president but JFK (and arguably Thomas Jefferson) has been a white Protestant male, and since almost all Presidential candidates fall into this group.

Six percent of the electorate may not be a problem for Obama if all of these voters are Republicans whose votes he wouldn’t expect in any case. But the Gallup poll also breaks out responses by political affiliation, and shows that 5% of liberals, 6% of moderates, and 8% of conservatives would not vote for a black candidate. If these numbers result in even a 1 or 2 percent handicap in the general election, this could be a major impediment for Obama. As a white Protestant male, John McCain doesn’t face this handicap – though it should be noted that the Gallup poll shows a significant handicap for a candidate of his age.

Opinion polls can be unreliable when the question asked has a socially acceptable response. Overt racism has become socially unacceptable in America, and that may cause people to hide their true views when answering questions on race and politics. Pew Research summarizes the difference between pre-election polls and actual results in biracial elections, and shows that once in the voting booth, many Americans are still not ready to vote for a black candidate. In the 80’s and 90’s, black candidates led in pre-election pools by double-digit margins, but went on to lose, or to win by narrow margins.

While the differential narrowed in 2006, it still seems that a few percent of the electorate will claim to support a black candidate, but change their mind in the voting booth. Since recent presidential elections have been decided by tiny margins, Obama still has a racial hurdle to clear in his race for the White House.