WASHINGTON -- The voting blocs that made winners of Hillary Rodham Clinton and John McCain in weekend presidential contests don't automatically spell victory for them in the contests next up.

Democrats vote in South Carolina on Saturday, followed by the Republican contest in Florida three days later.

Clinton won Nevada Democratic voters by capturing majorities of whites and Hispanics. Barack Obama got eight in 10 blacks in the campaign's first true test of the two rivals' appeal to that constituency.

But a different dynamic may await in South Carolina, where a repeat of that pattern by the state's racial groups might spell victory for Obama, an Illinois senator, because of the sheer number of blacks who make up the electorate. Should Obama get an emphatic majority of blacks there while whites give Clinton just more than half their vote, as they did in Nevada, Obama could have the numbers he needs.

Then there is the gender factor. Clinton beat Obama in Nevada by 13 percentage points among women while they split the male vote.

Republican presidential hopeful Sen. John McCain, R-Ariz., took the stage after his South Carolina presidential primary election win Saturday at The Citadel in Charleston, S.C. (Charles Dharapak ~ Associated Press)

A mid-January poll of South Carolina Democrats by Mason-Dixon Polling Research Inc. showed Clinton and Obama splitting women while Obama led among men. That, too, is a formula for an Obama victory.

As in Nevada, women are expected to make up nearly six in 10 Democratic voters in South Carolina, which could give Clinton an edge should she retain her recent hold on female voters.

The Republican race hopscotches down to Florida following McCain's narrow victory over Mike Huckabee in South Carolina. McCain heads into the Jan. 29 Florida primary heavily reliant on marginal segments of the GOP -- moderates, independents and less religious voters -- though exit polls of South Carolina voters showed signs he may be growing on the party's mainstream.

But it also presents the latest installment of a familiar test: Can he win the nomination without capturing its bedrock supporters, religious Christian and conservative voters?

Huckabee's losing coalition in South Carolina read like the GOP's honor roll: the very conservative, frequent church-goers, white born-again and evangelical Christians, those who want to deport illegal immigrants and make all abortions illegal, and people seeking a candidate who shares their values.

McCain's supporters were an assortment of Republicans who seldom call the shots in the GOP. It's a ragtag list: moderates, independents, those who are not born again or evangelical and people who pray only occasionally. Also, those who favor keeping at least some abortions legal and making some accommodations to illegal immigrants, are unhappy with President Bush and worry about the war in Iraq.