PEMBROKE, New Hampshire (CNN) -- Sen. John McCain enters to the sound of Chuck Berry's "Johnny B Goode." And he is smiling an optimistic smile.
"I am very happy about where we are," the Arizona senator told a crowd at the Pembroke Academy Wednesday morning. "The people of New Hampshire will make a selection that will have a significant, if not defining, impact on who the next president of the United States is."
His poll numbers in New Hampshire are up -- and there is talk of a comeback.
A CNN/WMUR poll, conducted by the University of New Hampshire and released Wednesday, has McCain and former Massachusetts Gov. Mitt Romney tied for first place, with each grabbing the support of 29 percent of likely New Hampshire Republican primary voters.
Former New York Mayor Rudy Giuliani is at 12 percent and former Arkansas Gov. Mike Huckabee is at 10 percent. The remaining Republican White House hopefuls are in single digits. The poll's margin of error was plus-or-minus 5 percentage points.
But there also are reminders of the obstacles for McCain.
Illegal immigration was the issue that most defined McCain's summer slide -- and it remains ever present.
"I don't believe in amnesty and how do you feel about that?" McCain was asked Wednesday morning.
He wanders toward the middle of the room, and turns to his trademark sarcasm.
"On the issue of illegal immigration, this meeting is adjourned.... Ha Ha."
The issue remains a potential vulnerability should rivals begin taking tougher aim at McCain. He still believes millions of illegal immigrants deserve some form of legal status -- a position that angers many conservatives.
But McCain's tone is different now than six or eight months ago. Now he stresses border security first, talks of finding and deporting or jailing illegals who have committed crimes, and also says that under his approach: "No one in this country would be rewarded for illegal behavior -- no one."
The improved poll numbers have McCain fans talking again of the possibility he could win the GOP nomination -- and the White House.
Some feel compelled to raise an issue that hasn't come up much since the early days, when McCain was a front-runner:
"I am wondering if you have the health and endurance to do eight years, because it is very demanding," a woman asked the 71-year-old senator at the town hall meeting.
"If I said that I was running for eight years, ha, I'm not sure that would be a vote getter," McCain said to laughter.
Turning more serious, he said he would take things one term at a time.
"We don't have time to waste," McCain said in Pembroke. "We don't have eight years to fix Social Security or Medicare. We don't have eight years to secure our borders so we can stop the flow of illegals into our country. We don't have eight years. We have got to get going from day one."
He told reporters later talk of one term at a time has nothing to do with his age.
"I think every president in history has focused on his first term and then evaluated after the first two or three years whether he wants to run for re-election or not."
New Hampshire is McCain's defining test -- and he knows the expectations.
"I think it has to be perceived as a win, yes," McCain told reporters.
On hand to help with the closing argument in New Hampshire was Sen. Joseph Lieberman, the Connecticut Democrat turned independent, who echoes McCain's theme of experience.
"Who has the strength, the experience, the character to keep us safe and unite the country to solve some of our problems -- and that is John McCain," Lieberman said at a later stop at a diner in Derry, New Hampshire.
After a bacon and egg sandwich for lunch, there was a more humorous go-round on the health and age issue. When a reporter raised the issue, the senator bent over and stumbled into the crowd of reporters.
Laughing, he looked up -- again smiling. "Look, it is great. Just come with us on the campaign trail. We out-campaign everyone. I am exuberant."
From there it was off to Iowa for one last push. McCain hasn't campaigned there much, but is hoping he can surprise people with a third-place finish. E-mail to a friend