John McCain introduced Alaska Gov. Sarah Palin to be his vice presidential running mate at a noon rally here Friday.

“My friends and fellow Americans, I am very pleased and very privileged to introduce to you, the next vice president of the United States, Governor Sarah Palin of the great state of Alaska,” McCain told a capacity crowd of 12,000 at the Nutter Center.

Sen. Barack Obama is bracing for the general election fight, and conservatives are likely to throw some jabs at his wife Michelle Obama as well.

Conservatives view the presumptive Democratic nominee's wife as a target of opportunity.

But one Republican consultant said attacks on candidates' wives often backfire.

Sen. John McCain cemented his Republican front-runner status Tuesday, piling up big wins coast-to- coast, according to CNN projections.

Democratic voters remain evenly split on Sen. Hillary Clinton and Sen. Barack Obama for their party's nomination.

The presidential races head to key primaries in Virginia, Maryland and the District of Columbia next Tuesday. The candidates hope to gain momentum for those with victories in the Louisiana primaries and Washington state caucuses on Saturday.

In what could be a pivotal day for the Democratic and Republican White House hopefuls, voters coast to coast will head to the polls in 24 states and American Samoa Tuesday.

Super Tuesday is virtually a national primary day, and some of the biggest prizes of the primary season -- California, New York, Illinois, New Jersey, Missouri and Georgia -- are up for grabs.

More than four-fifths of the 2,025 delegates needed to clinch the Democratic presidential nomination and more than 1,000 of the 1,191 necessary delegates on the Republican side are at stake.

Former New York Mayor Rudy Giuliani plans to drop out of the presidential race and endorse McCain at an event in California, two GOP sources with direct knowledge of the plans said.

Giuliani was a distant third with the results from Tuesday's voting almost final.

While Giuliani didn't say he was withdrawing from the race, he did speak of his campaign in the past tense at one point.

"I'm proud I ran a positive campaign," he told supporters. "I ran a campaign that was uplifting."

Senator John McCain defeated Mitt Romney on Tuesday to win the delegate-rich Florida primary, solidifying his transformation to the Republican front-runner and dealing a devastating blow to the presidential hopes of Rudolph W. Giuliani.

Sen. John McCain of Arizona and former Arkansas Gov. Mike Huckabee are in a close race for first in South Carolina, according to exit polls.
Former Tennessee Sen. Fred Thompson and former Massachusetts Gov. Mitt Romney are vying for third place in the pivotal Republican primary.

Results from the GOP primary come just hours after the Nevada caucuses.

Sen. Hillary Clinton won Nevada's Democratic caucuses and Romney claimed victory on the Republican side, according to CNN projections.

Clinton, coming off a disappointing third-place finish in Iowa, rebounded to first place, overcoming rival Sen. Barack Obama in the state's Democratic primary.

The win breathes new life into a Democratic campaign that turns its focus to contests in Nevada and South Carolina -- and could stretch past "Super Tuesday" February 5.

Supporters at Clinton's headquarters chanted "comeback kid" as the results arrived.

Clinton had trailed Obama by 9 points in recent polls. Video Watch what's next for campaigns »

Sen. Barack Obama, bidding to be the first black president in American history, won the Iowa caucuses Thursday night, pushing Sen. Hillary Clinton back to third place in the opening test of the race for the Democratic presidential nomination.

On the Republican side, Mike Huckabee rode a wave of support from evangelical Christians to victory over Mitt Romney.

Obama, 46, told a raucous victory rally his triumph showed that in "big cities and small towns, you came together to say, 'We are one nation, we are one people and our time for change has come.'"