“This is about winning at the end of the day,” said John Weaver, Mr. McCain’s longtime senior strategist. “I don’t want to be in a knife fight ever again, but if I am, we’re going to win it.”

Mr. McCain’s representatives said he would not provide an interview.

Seven years ago, Mr. McCain charmed the news media and the public with his Straight Talk Express bus tour. He had a lean operation befitting an upstart candidacy, and he regularly spoke out against attack advertising, a quaint notion in retrospect.

In the end, he ran his share of confrontational advertisements, once even leveling the ultimate Republican-to-Republican insult: that Mr. Bush was as dishonest as Bill Clinton. But he was perceived as having been knocked back on his heels by the rougher, tougher Bush campaign.

Now Mr. McCain is building a larger organization, bringing together the heart of the bare-knuckled Bush crew once overseen by Karl Rove while keeping most of the advisers who ran his shoestring effort of 2000.

“It’s like an all-star World Wrestling Federation cage match, except that instead of fighting one another, all of the brawlers are on the same team,” said Steve McMahon, a strategist for the Democratic National Committee. “There are very few people who play this game at the highest level, and on the Republican side these guys are among the best.”

Mr. McCain has also hired Brian Jones, an adviser to Mr. Bush’s 2004 campaign; Fred Davis, a media consultant for Mr. Bush in 2004; and Steve Schmidt, who oversaw Mr. Bush’s 2004 war room, exploiting any tidbit that could help paint Mr. Kerry as a “flip-flopper.”

The hires are another signal that the 2008 primary campaign could be a combative one all around.

On the Democratic side, John Edwards, the former senator from North Carolina, has wasted no time attacking Senator Hillary Rodham Clinton’s position on Iraq. And Mrs. Clinton’s team includes strategists who invented the concept of the modern campaign war room for her husband 15 years ago. But Senator Barack Obama of Illinois drew cheers at a party gathering on Friday when he warned his fellow candidates against attacking one another.