WASHINGTON — Perhaps it was inevitable: The Democrats’ battle for the presidential nomination has now led us into the thicket of race and religion.

Hillary Clinton’s significant victory over Barack Obama in the Pennsylvania primary was the result of many factors, but most troubling for Obama’s camp were exit polls suggesting that an underlying anti-Obama vote was responsible for the size of Clinton’s victory.

One little-noticed finding was that 6 percent of Clinton’s own voters said that they would defect to John McCain in the fall against Clinton herself. These Pennsylvania Democrats were clearly not Clinton enthusiasts. They were voting against Obama.

What was behind the anti-Obama feeling? More specifically, did Obama’s race play a role? The evidence suggests that race mattered; it’s just not clear how much.

Among white Pennsylvania voters, roughly one in six said race was a factor, and three-quarters of them voted for Clinton. By contrast, Clinton’s gender seemed to help her more than hurt her: A substantial majority of men who said a candidate’s gender was a factor (a very small group) voted for Clinton.

The import of race was widely debated in e-mail discussion groups and on Web sites from the moment the exit polls became available. There is certainly a danger of exaggerating the impact of race in Pennsylvania, since Clinton also beat Obama by about 3 to 2 among whites who said race played no role in their decision.

Nonetheless, elections are usually decided at the margins, and these findings will (and should) prompt a more open and candid discussion of race’s role this year.

Republicans clearly know that they can find ways to play on racial feeling while fully denying they are doing so. On Wednesday, the North Carolina Republican Party released a television ad showing Obama’s former pastor, the Rev. Jeremiah Wright, giving his now-famous sermon in which he declared, “God damn America.”

Of course Wright’s comments were offensive, but to pretend that the ad does not have racial undertones would be to deny the obvious. After all, why didn’t North Carolina Republicans focus instead on attacking Obama’s alleged “elitism” or his foreign policy views?

And a pattern was set that may define the rest of the campaign: Will John McCain be able to profit from incendiary ads run by his partisan allies even as he insists he would never run such ads himself?

The religious factor, and specifically the Catholic factor, is equally complicated. But it is no less important. Among white Catholics in Pennsylvania, Clinton received 72 percent of the vote, nine points better than her share among whites as a whole and 13 points better than her performance among white Protestants.

Some of the differences can be explained by the fact that self-identified Pennsylvania Catholics were older than other voters — and older white voters have been at the core of Clinton’s base. Among voters under 45, by contrast, the differences between white Catholics and white Protestants were negligible.

Nonetheless, older white Catholics were decidedly more resistant to Obama than other older whites. Even as Pennsylvania’s votes were being counted, a top Clinton campaign official was touting the extensive work Clinton had done to woo Catholics.

He spoke of campaigning by nuns around the state, a special “Catholic conversation” hosted by some of Clinton’s prominent Catholic supporters just before CNN’s “Compassion Forum,” and even of the fact that Chelsea Clinton had attended Mass at St. Christopher’s parish in northeast Philadelphia with Catholic supporters.

The Obama campaign was slower in organizing Catholics, but earlier this month announced the formation of a Catholic “advisory council” whose ranks include Sharon Daly, a former top official at Catholic Charities USA, and Mary Jo Bane, who served in the Department of Health and Human Services in Bill Clinton’s administration. Since Catholics have a history of backing the ultimately victorious presidential candidate, the struggle over Catholic voters will be closely tied to arguments with superdelegates over whether Clinton or Obama is the more electable Democrat.

But the debate over what happened in Pennsylvania is, finally, an argument over whether 2008 really is the year when the patterns of the past will be broken.

Will younger voters or older voters set the tone of the campaign? Will past divisions over race and religion reassert themselves, or will the electorate decide to push them aside in the interest of a new 21st-century politics? Never has Obama’s slogan, “Yes We Can,” seemed more relevant to his political task.

E.J. Dionne’s e-mail address is postchat(at)aol.com.

© 2008, Washington Post Writers Group

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