You can hear it everywhere, especially from Barack Obama’s supporters: “If Obama loses, it will be because so many voters are racist.”

Whether that turns out to be true, it casts a shadow on an important chapter in American history and American Jewish history.

In 1982, pre-election polls indicated that Tom Bradley, the African American candidate for governor of California, would win the election. On Election Day, he received 5 percent fewer votes than the polls had indicated — and lost. Some analysts surmised white voters either lied to the pollsters about how they would vote or changed their mind in the voting booth, a phenomenon termed the “Bradley effect.”

Whether the Bradley effect was true or exaggerated, we should not overlook another factor: the cumulative or delayed effect of the civil rights movement.

In his 2006 book, “The Audacity of Hope,” Obama wrote that the civil rights movement had established “the simple principle of nondiscrimination [that] was sufficient to pull the large majority of blacks and Latinos into the socioeconomic mainstream within a generation.”

It had a similar effect for American Jews.

Seventy years ago, anti-Semitism was at its peak in the United States. Every week on the radio, Father Coughlin spewed Jew-hatred to his millions of followers. About half of all Americans admitted to strong prejudices. They thought most Jewish businessmen were crooks, they would never vote for a Jewish candidate for president and they would never hire Jews.

Although American Jewish organizations had long mounted educational campaigns against this form of anti-Semitism, it continued to grow in the United States through World War II, after which the American Jewish community revolutionized its fight against anti-Semitism.

In the early 1950s, the new Jewish community relations network established these practical working principles: “Equal rights and opportunities for Jews can be realized only in a society in which all persons are secure, whatever their religion, race or origin,” and, “Changing social behavior is often the best way to change social attitudes.” On those grounds, among others, the Jewish community became a prominent part of the civil rights movement in its crucial legislative period.

The civil rights laws were successful — they changed behavior, created new spheres of integration and proved to be the most effective tool against anti-Semitism, as well as prejudice against African Americans. Before the civil rights laws were passed, a third of Americans said colleges should maintain low quotas for Jewish applicants. Half of American employers said they would resist hiring Jews.

About 25 years after the civil rights laws were passed, fewer than one in 10 Americans approved of the college quotas or said they would resist hiring Jews. Actual discrimination in colleges and workplaces had dropped accordingly.

Now there is an undercurrent of comment around the country that some Jews are opposing Obama because he is African American. The supposed evidence is that Jews are not supporting Obama as strongly as they usually back Democratic Party presidential candidates.

An American Jewish Committee poll released in September found American Jews favoring Obama over his Republican opponent, Sen. John McCain, by 57 to 30 percent. In 2004, about 75 percent of American Jews voted for Sen. John Kerry, the Democrat’s candidate for president. For some 80 years, American Jews have been voting for the Democratic Party presidential candidates at a rate about 15 to 25 percent higher than that of other Americans.

While Jews will probably vote for Obama in a higher proportion than any group in America other than African Americans, that vote might be smaller than the usual Jewish vote for a Democratic candidate. The cause is not a sudden increase of race prejudice among Jews, but a concern about Obama’s foreign policy credentials. That concern might be right or wrong, but it is a concern about a policy issue, not about skin color. It would be irresponsible, even dangerous, to suggest otherwise, either for Jews or for Americans in general.

Earl Raab is a former executive director of the S.F.-based Jewish Community Relations Council.

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