Overconfidence is a big problem for those supporting President Obama — so much so that Anita Dunn, his former communications director, said it was one of her three concerns for the campaign. After the month Mitt Romney has had, Obama supporters should be forgiven being overcome by overconfidence. But last night’s “60 Minutes” should snap them out of it.

Obama and Romney were both interviewed for the venerable CBS News program. We’re used to seeing the president do well in those settings. We’re not used to seeing Romney do well. And he did. I’m not saying the Republican presidential nominee was a fount of policy substance or clued us in on his vision of America with him as president. But he was a vision of unblinking confidence.

Romney’s answers were crisp, to the point and evasive. When CBS’s Scott Pelley asked which deductions and loopholes he’d eliminate as part of tax reform, Romney was evasive but not defensive. “Well, that’s something Congress and I will have to work out together,” he said. “The devil’s in the details. The angel’s in the policy, which is creating jobs.”

“Some people, governor,” Pelley said, “have an uneasy feeling that you’re not constant. That you say whatever you have to say in a articular moment.” Romney deflected by harping on promises made and positions held by Obama that have since changed.

“People wonder,” Pelley pressed, “‘Does Romney believe the things that he says?’ You say what to those people?”

Romney responded:

The principles I have are the principles I’ve had from the beginning of my political life. But have I learned? Have I found that some things I thought would be effective turned out not to be effective? Absolutely. If you don’t learn from experience, you don’t learn from your mistakes. Why, you know, you ought to be fired.

He said this with utmost sincerity. And it’s not like his overall lesson about learning from experience would strike any reasonable person as odd. That’s the thing about his “60 Minutes” musings. Romney sounded reasonable. He didn’t sound like the guy who trashed half the country during a fundraiser in May.

But as we saw through a slew of debates during the Republican primaries, Romney is also a good debater. And according to James Fallows of The Atlantic, Romney has consistently used five tactics in debates since he unveiled them at his 1994 debate with the late Sen. Ted Kennedy. Fallows notes that Romney comes “prepared to defend” himself and his candidacy. He has counterarguments for whatever his opponent throws at him. He finds a way to “politely insult” his opponent. He shows “a flash of sly wit.” And he is “unwaveringly on message.”

All those tactics were on display last night on “60 Minutes.” If that Romney shows up at the debate in Denver on Oct. 3 and Obama lives up to his reputation for being a bad debater, we could be just a week away from stories declaring a reset for Romney.