What happened to the old John McCain?
It's a question often asked about the senator once known for working with Democrats and driving his own party crazy, who is now seen as a party-line conservative.
In an exclusive ABC News Subway Series interview, McCain asked, and answered, the question himself.
"I heard that during the presidential campaign, too. 'What happened to the old John McCain?' Then I heard it in the primary: 'What happened to the old John McCain?' Who was the old John McCain?" McCain said. "The old John McCain and the new John -- the present John McCain -- I fight for what I believe in. I'm a fighter. I enjoy -- one of the reasons I miss Ted Kennedy so much -- it's because a fight not joined is a fight not enjoyed."
In the interview, conducted aboard the subway that runs beneath the U.S. Capitol building, McCain made it clear the fights he's joining these days are against President Obama and Democrats in Congress, taking a hard line against the president on health care and defending Sen. Jim Bunning's action this week to block an extension of unemployment insurance.
On health care reform, McCain called the Democrats' bill "the worst example of vote buying in my years here," and warned of dire consequences for the rest of the Obama agenda if Democrats try to push health care overhaul through the Senate using reconciliation, a parliamentary tactic requiring a simple majority of 51 votes.
"I think what's going to happen is you're going to poison the environment here for the rest of the year, because we think this is really the wrong thing to do," McCain said. "But maybe more importantly, the American people will be even more vigorous in November in displaying their anger at what the Democrats have done."
McCain said he is "in empathy" with Bunning, the Kentucky Republican, for his decision to tie the Senate up in knots, preventing the renewal of unemployment benefits for a week because the bill was not paid for with cuts to other programs.
"Jim Bunning exercised his rights as a senator," McCain said. "I respect those rights. And he was making a point that many Americans believe is legitimate. That is: we keep passing these quote 'emergency' spending, even though they're necessary -- we make no effort to pay for them because we call them a quote 'emergency.' Now, some of them are an emergency, but what Jim's point was -- and I think he made it, and it reverberated around the country -- is, we got to stop the spending and make tough decisions on that."
McCain said a Republican takeover of Congress in this year's mid-term elections is "a very likely possibility."
Asked if Barack Obama will be a one-term president, McCain paused and then said, "I don't know. I don't know the answer to that. But I do believe that they are governing from the left, and America is a right-of-center nation."
McCain, who is up for re-election this year, is facing a primary challenge from conservative talk radio host and former congressman J.D. Hayworth. He made it clear he is taking Hayworth's challenge seriously.
"I have taken every race that I have ever been in with the utmost seriousness, and I'm not running on my record," McCain said. "I'm running on that I know I have to earn every vote. Too many incumbents -- you and I know -- believe that people will be grateful to them. That's not why I vote for people. I know I need to earn every vote."
Does he still like his job?
"Oh, I love it. I love it," McCain said. "And I've enjoyed the last year enormously. Listen, as I said, a fight not joined is a fight not enjoyed."