Following disappointing showings in the nation's Super Tuesday primaries and caucuses, Bill Bradley and John S. McCain dropped out of the presidential race in rapid order yesterday, ensuring that the Democratic and Republican nominations will go to Vice President Al Gore '69 and Texas Gov. George W. Bush.

On Tuesday, McCain only managed four victories--in Connecticut, Massachusetts, Rhode Island and Vermont--in the 13 Republican contests, while Gore swept all 16 Democratic primaries and caucuses.

Yesterday morning, as expected, they both withdrew from the race, each vowing to keep fighting for the issues they believe in.

"We have been defeated but our cause has not," Bradley said at a news conference in West Orange, N.J. He vowed that he would continue to fight for his signature issues of improved race relations, health care and campaign finance reform.

While Bradley did not release the 412 delegates he has won--so they will have a voice at the Democratic National Convention in August--he immediately endorsed Gore for the presidency.

"I believe a Democratic president can do more for this country than a Republican president can," Bradley said. He added that Gore has his "full support" and that now is the "time for unity" to win the White House.

Bradley said his campaign failed because unions and the Democratic party establishment supported Gore and because he failed to communicate that his candidacy was not one of "self interest."

"It certainly shows that when you do battle with entrenched power that it's very difficult and, indeed, I think that's what the story of the campaign was," Bradley said.

While Bradley said he would not run as a vice presidential nominee with Gore, aides say he could run for the presidency again in 2004 or 2008.

About an hour after Bradley's announcement, McCain announced from his retreat in Sedona, Ariz. that he was suspending his campaign.

"I am no longer an active candidate for my party's nomination," McCain said. "A majority of Republican voters made clear that their preference for president is Governor Bush...I respect their decision."

He said he would continue to work for reforms on Social Security, Medicare and his signature issue, campaign finance reform.

"I will take our crusade back to the U.S. Senate," McCain said, adding that he wants to reform "a tax code that benefits the powerful few at the expense of many."

McCain thanked the many Republican, Democratic and independent voters who supported him during the course of his campaign and urged them to stay active in the political process.

"Our crusade will never achieve all of its goals if your voices fall silent in the national debate," McCain said.

One of every four GOP primary participants in this year's elections had never before voted in a Republican contest.

"He energized a lot of voters and a lot of people who wouldn't have voted," said Thomas R. Snider, a Harvard Law School student and a coordinator for Massachusetts Youth for McCain. "A lot of people were looking...for a non-establishment figure."

While Bradley said he would withdraw completely from the race, McCain said only that he will no longer actively campaign for delegates, and did not endorse Bush's campaign, instead giving him his "best wishes."

Seeking to eliminate speculation that he will reappear in the race as the Reform Party candidate in the fall, McCain reaffirmed his commitment to the Republican Party.

"I love my party," he said.

Despite their candidates' failure to win their parties' nominations, Bradley and McCain supporters at Harvard said their candidates brought important issues to the forefront of the race.

"I'm really proud of what he's been able to achieve...in terms of what

this year's election debate is going to be about," said Luke P. McLoughlin '00, president of Harvard Students for Bradley.

Last summer, McLoughlin said, Gore was talking about a 1-800 number for traffic congestion, an airplane passengers' bill of rights and urban sprawl.

"Now we're talking about universal health care, campaign finance reform, poverty, and race. That's Bradley's doing," McLoughlin said.

Bradley supporter John E. Raskin '03 said he was "sorry to see [his candidate] go."

"It was really nice to work for a candidate I genuinely believe in, someone who wasn't the lesser of two evils," Raskin said.

"A lot of the issues Bradley identified with will become more and more mainstream over the next decade or so," Raskin added.

Snider said he is not sure why McCain "suspended" his campaign instead of dropping out of the race altogether.

He said he thinks that McCain did not endorse Bush yesterday because he wants his sometimes-bitter rival to reach out to him.

"McCain's waiting for Bush to apologize for some of the negative campaigning that went on," Snider said, adding that "it would make sense" for McCain to endorse Bush now that Bush is taking up the mantle of reformer.

Snider said he appreciated the genuine enthusiasm McCain expressed to his campaign volunteers. Before McCain entered town hall meetings in New Hampshire, he would stop and personally thank all 10 to 15 members of his advance team, Snider said.

"He really showed a lot of genuine appreciation for the people who helped him out," Snider said.

Supporters of the candidates said numerous obstacles made it difficult for their candidates.

Raskin said Gore's party backing made it difficult for Bradley to win.

"It's hard to be a reformer and challenge the establishment," he said.

McLoughlin said that too many primaries are held too early in the election season.

"So many delegates are decided so early now, it's only going to accelerate that crowning process," he said.

And Mattie Germer '03, who organized Harvard undergraduates for McCain, said Bush and Gore's nominations underscores the role "big money" plays in the election process.

"I think it is very discouraging that party bosses and party elites can coronate their chosen nominees and "persuade" the American public to validate their decisions," Germer wrote in an e-mail message. "I think that the large minority of voters who supported John McCain and Bill Bradley feel even more alienated from the political process than they did before."

Kennedy School Lecturer Martin A. Linsky said it is common in American politics for party nominations to seem preordained, however.

"There are very few insurgent candidacies that have ever been successful," Linsky said, giving John Anderson, Ross Perot and Teddy Roosevelt, Class of 1880, as examples. "Most of the examples cut the other way."

In Washington, President Clinton said Bradley's withdrawal reflected the differences between the two parties' contests.

"It recalled again how very much more substantive the debate was on the Democratic side on the issues and how much more agreement there was," Clinton said.

Bush and Gore, meanwhile, have already begun jousting in their race for the presidency.

"For too long we have seen politics which wants to diminish the soul of America," Bush said at a campaign rally in Colorado, referring to the Clinton Administration.

Seeking to pick up McCain's mantle of education reformer, Bush said he agreed with McCain that the Washington government needs to be reformed.

"In order to reform Washington, D.C., it's important to get rid of Clinton-Gore," Bush said.

With eight months to go before November's general election, Gore and Bush are in a dead heat for the presidency.

A MSNBC poll taken Wednesday showed Gore leading Bush 43 to 40 percent.

--Wire reports were used in the reporting of this story.