"We're voting against Obama," said Limbaugh, who -- as Sen. Mitch McConnell has done in Congress -- has fixed as the top GOP goal removing the first black U.S. president from the White House. Such assertions "may have a strong appeal to those who have latent racial motivation," according to a recent Washington University study of some 8,600 voters, 80 percent of them whites.

This refrain, sometimes made with dog whistle, is played by key GOP leaders such as Romney's adviser, former Gov. John Sununu, who called Obama "lazy and detached." Such stereotyping was floated on Facebook just this week by former GOP vice presidential nominee Sarah Palin, who, in criticizing U.S. handling of the Benghazi, Libya, consulate attack, wrote that "President Obama's shuck and jive shtick" must end.      

While ideological GOP loyalists cite policy stances on such issues as the economy and health care for supporting their candidate, the Washington University report concluded that among undecided voters, race bias influenced the choice of some 10 percent of white voters, said Anthony Greenwald, a professor who developed the "Implicit Association Test" to measure such attitudes. Among decided voters, he calculated that race bias influenced only 2.4 percent of participants.

"Eligible voters who favored whites over blacks -- either consciously or unconsciously -- also favored Republican candidates relative to Barack Obama," wrote Molly McElroy about the large-scale WU study by a group of psychologists.

Working with the demographics of the GOP, Romney has kept the faith with his white base. In his appearance before the normally overtly polite NAACP convention, Romney was booed for promising to repeal the signature achievement of the first black president -- on day one of his administration! The following day, he suggested that such "Obamacare" supporters simply "want more free stuff from the government," and should not vote for him.

Should such voters take Romney's insult literally, they would likely vote against him 95 percent, much as they did against McCain-Palin, who similarly snubbed black voters.

Unfolding before our very eyes in the upcoming election is something of a racial showdown between an incumbent black president who has enjoyed 43 percent white support and a shifty character from the Republican Party, which is 98 percent white.

Stay tuned.

Les Payne is a Pulitzer Prize-winning journalist and frequent contributor to The Root.

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