Washington ? Sen. John McCain’s “Straight Talk Express” has been in the repair shop for a while, but it sure was rolling last week during an interview. The main theme was that Republicans should end their self-isolation and “start working for the American people.”

Journalists have always had a soft spot for McCain when he’s in the mode of bipartisan conciliator. And I don’t want to overstate the evidence of an hour-long conversation the other day in McCain’s Senate office. He remains a complex and mercurial man whose support for centrist policies has ebbed and flowed over the years. But he’s definitely in outreach gear right now.

What seems to perturb McCain most is some Republicans’ willingness to harm the military as part of “sequestration” budget cuts. You can hear the Vietnam veteran and former POW speaking when McCain describes the military impact as “so appalling I can’t describe to you how upset I am.”

The Arizona Republican denounces congressional moves that will idle Navy carriers and reduce the readiness of the Marine Corps. Meanwhile, he complains that the “continuing resolution” will spend $5 million on a needless Pentagon science program for elementary schools and $11 million on a volunteer civil air program, and prohibit the retirement of C-23 aircraft the Army doesn’t want and state governors have rejected. This tirade about pork-barrel spending is vintage McCain, but what’s interesting is that much of the ferocity is toward his own party.

Why is the GOP bending toward its isolationist wing? McCain says the party is suffering from “war weariness,” and from its continued stress on spending cuts to the exclusion of other issues.

Early in the interview, McCain mentioned that he has been talking with President Obama about immigration reform. When I asked if he had also raised Syria, where McCain has been sharply critical of administration passivity, he said no: “I don’t want to get into an argument with the president.” That’s interesting for a combative man who often can’t resist a zinger.

McCain said he is talking bipartisanship now because “I really believe the American people are fed up.” He joked about a survey showing that Congress is less popular with the public than a colonoscopy as evidence that “we are really in serious trouble,” and that “Americans want us to work together.” He pointed to compromises he’s trying to work out with Senate Democrats such as Carl Levin, Chuck Schumer and even Majority Leader Harry Reid.

During Obama’s first term, McCain says he tried to reach out on issues such as immigration, and was spurned. But here, too, he is self-critical: “I will admit to not cooperating as much as I should have.” He says he’s now eager to work with Obama on immigration reform, campaign finance, sequestration, and a “grand bargain” on budget issues.

“The president and I have established what I believe is a working relationship,” McCain said, citing his role in Obama’s celebrated dinner with Republican senators at the Jefferson Hotel this month.

McCain said many other prominent Republicans share his view that it’s time to walk back from the partisan cliff. “There is an attitude change on the part of people who want to get this done for the American people. All politicians crave approval. That’s part of our DNA. When there’s such strong disapproval, that has an effect.”

“The Republicans have a problem,” he added bluntly. “The president’s (approval) numbers are going down, but not nearly as much as the Republicans’.” He cited the unsuccessful GOP Senate campaigns last November of Richard Mourdock in Indiana and Todd Akin in Missouri as evidence that “if we nominate people outside the mainstream, we’re going to pay for it.”

What accounts for McCain’s new tone, and the return of the happy warrior of the center? Certainly, he’s prickly about recent comments that his jihad against Hagel showed he had become “bitter” or “angry.” Not so, he insisted. After surviving torture in a North Vietnamese prison and cancer surgery, “I’m the luckiest man who ever lived. I should have gone a long time ago. I don’t want to look back on any wasted days.”