The Bradley Effect is a phenomenon characterized by the tendency of non-white political candidates to perform better in opinion polls than they do in actual elections when they are running against white candidates. Most specifically, this effect often strikes black politicians, although it can just as easily affect Hispanics and other minorities. This interesting phenomenon has been a topic of intense study by pollsters, political analysts, and others, and there are several theories used to explain the Bradley effect, which is sometimes also known as the Wilder Effect.

The concept is named for Tom Bradley, an African-American man who ran for the office of Governor of California in 1982. In polls leading up to the election, Bradley had a clear lead, and numerous media outlets boldly projected that he would win the election. On election night, however, he lost to the Republican candidate, much to the puzzlement of the Democratic party and many Californians. The same thing happened in Virginia in 1989 in another gubernatorial race, and numerous other instances of the Bradley effect have been documented at various points in American history.

One of the primary explanations for this phenomenon is racial. Pollsters have suggested that voters may not want to admit to planning to vote against a black candidate, because they fear being perceived as racist, especially when the pollster is black. Polling organizations have also suggested that the Bradley Effect could be caused by undecided voters, many of whom lean in a conservative direction on election night.

This effect appears to be diminishing in American society, for a variety of reasons, but it is still a present and interesting issue. Researchers are curious to learn about the mechanics of this phenomenon in the hopes of learning more about American politics and cultural beliefs. The rise of minority candidates in the United States will undoubtedly, and somewhat regrettably, provide more instances of the Bradley Effect, as Hispanics, Asians, and other minorities attempt to break into American politics on the state and national level.

In 2008, an interesting reversal of the Bradley Effect occurred in Iowa, when black Democratic Presidential candidate Barack Obama fared better than expected against the white candidate, Hillary Rodham Clinton, in the caucuses of that state. Some political pundits suggested that because caucuses are public, some voters might have felt pressured into supporting Obama out of a desire to appear liberal and open-minded in front of their neighbors.