MANCHESTER, N.H. ? Two hours before Fred Thompson formally entered the race for the Republican presidential nomination, his old friend John McCain turned in the kind of performance that once would have kept Thompson from running.

As eight GOP hopefuls debated Wednesday night at the University of New Hampshire and on Fox News, McCain enjoyed the best 90 minutes since his campaign started spiraling downhill last spring. He received accolades from his rivals and from the audience – raising at least faint hopes of his revival in the state where he defeated George W. Bush in 2000.

When I interviewed Thompson last month about his planned candidacy, he was frank to say that if McCain had not stumbled so badly in the first half of 2007, there would have been no opening – and no cause – for Thompson to run. “I expected to support John, just as I did in 2000,” Thompson said.

Like other Republicans, Thompson said he was mystified how McCain, with all his advantages, lost control of his campaign organization and budget, how he ran through millions of dollars, shed his staff and found himself in early summer dead-broke and scrambling for help. “I guess it could happen to anyone,” Thompson said.

But even as Thompson was making the decision to run, McCain was regearing for an uphill fight.

Three steps have been crucial. His outspoken support for the “surge” strategy in Iraq had to find a degree of endorsement from real-world events. The edge had to come off the issue of illegal immigration, which had caused him deep political wounds. And he had to re-establish his personal contact with voters in New Hampshire and remind them why they had once been for him.

He still faces formidable obstacles. Mitt Romney has taken the lead here and has an impressive organization. Rudy Giuliani is competing well for moderate Republicans. And independents, who gave McCain his victory in 2000, are likely to flock to the Democratic primary this time – making Barack Obama a greater threat to McCain than Bill Bradley was in 2000.

Still, as the fall campaign season begins – and as the Durham debate demonstrated – McCain has begun to achieve all three goals.

On Iraq, an assertive McCain chided Romney for hedging his bets by saying that the surge “apparently” is meeting its military objectives. “It is working,” McCain told the former Massachusetts governor. “Not ‘apparently’; it’s working.”

McCain expects validation of that view from Gen. David Petraeus this week, and is eager to be Petraeus’ advocate when the Senate takes up the issue – while at the same time reminding people that he was one of the first critics of the previous strategy under Don Rumsfeld.

On immigration, where McCain was particularly vulnerable as co-sponsor with Ted Kennedy of the failed comprehensive legislation endorsed by Bush, he has bowed to reality. Blaming the failure of that bill on the public’s loss of confidence in government, McCain now says that the first step must be securing the border – and having that success certified by the border state governors.

But as important as these changes have been, the key for McCain has been returning to the town-meeting formats that worked so well for him here before – lengthy and uninhibited question-and-answer sessions that allow him to display his command of substance, his candor and his sense of humor.

That ease and intimacy have carried over to his debate performances. He opened Wednesday night by suggesting slyly that Thompson might be skipping the debate (for the Jay Leno show) because “we’re up past his bedtime.”

After making his points about Iraq and immigration, he smiled contentedly as Romney and Giuliani struggled to answer tough questions about their personal histories – questions that raised doubts about their credibility.

And then he received an unsolicited testimonial from rival Mike Huckabee, as the former Arkansas governor complimented McCain for setting “honor” as the criterion for American policy in the war. “If there’s anybody on this stage that understands the word ‘honor,’ I’ve got to say Sen. McCain understands that word,” said Huckabee of the former Vietnam POW.

Unsurprisingly, a Fox focus group in Manchester named McCain as the debate winner, and Dante Scala, a UNH political scientist, told a politically oriented Web site, “If New Hampshire Republicans were tuning in, they’re probably thinking to themselves, ‘That’s the John McCain I remember.'”

To top it off, the Concord Monitor on Thursday editorialized that McCain is “good at the kind of campaigning that wins elections here. That’s no accident. As much as any candidate in recent memory, McCain respects – and embraces – the New Hampshire primary,” with its emphasis on person-to-person communication.

Fred Thompson, take note.