The most revealing aspect of Mitt Romney’s tense interview with Fox’s Bret Baier was the look that crept onto the former governor’s face: that of a boxer cruising to victory who can’t believe his opponent has just risen from the mat again. Romney seems to be living through his own version of the famous Monty Python scene, “Nobody expects the Spanish Inquisition!” No one, and certainly not Romney, expected Newt Gingrich.

But ready or not, here comes Newt. And Romney was decidedly not ready. Yet it’s easy to understand why. A look back at Romney’s relationship with the conservative movement during the last three years offered no preview that he would be unceremoniously dropped, certainly not for Gingrich. To watch Romney’s speech to the Conservative Political Action Conference (CPAC) in 2008–and again in 2009 and 2010–is to begin to understand the suddenly staggering former frontrunner.

When Romney took the stage at CPAC in 2008, it was to announce his withdrawal from the race in order to consolidate Republican support around John McCain. But apart from the atmospherics–Romney was introduced by Laura Ingraham and the crowd practically begged him to take his candidacy all the way to the convention–the speech itself seemed to solidify his membership in the conservative movement.

America is strong, Romney said, but warned that “The threat to our culture comes from within…. Dependency is death to initiative, risk-taking and opportunity. Dependency is culture killing. It’s a drug. We’ve got to fight it like the poison it is.”

He received standing ovations. There was a sense from the audience that giving up on Romney’s candidacy was giving up on the conservative fight–at least for now. The following year, Romney returned to a hero’s welcome. McCain had lost, just as conservatives predicted when they warned of nominating an erratic compromiser. The year after that, 2010, Romney’s appearance at CPAC received rave reviews. But 2011, for Romney, had none of that magic. Something had happened in the interim: President Obama had forced through Congress and over the objections of the American people his signature initiative, Obamacare.

And just like that, the wheels began to come off the Romney train. Last year’s CPAC conference was full of the passion conservative activists bring to the cause–only the source of much of that passion was opposition to Obamacare. How could Romney credibly attack Obamacare?

It’s true there are major differences between Romney’s health care overhaul and that of Obama. But the distinctions were less about which mandate is constitutional and more about the idea behind them–the culture they threatened. Ask conservative activists why they’ve changed their tune on Romney, and some of them will say Obamacare. But many of them won’t put that fine a point on it. Many will say they just don’t trust him. He’s just not one of them.

It’s understandable. Romney has the air of a detached politician, not a genuine conservative warrior. He has switched positions on issues near and dear to the conservative cause, and it’s only fair that his sincerity is questioned. But he thought he put all that behind him.

“I’m going to be the nominee,” Gingrich told ABC News yesterday. And he might be. In the movie “Any Given Sunday,” the football team assembles in the locker room before the big game, where their coach (Al Pacino) gives an oft-quoted pregame speech centering on the difference it makes to fight for the extra inch, every time. “Now I can’t make you do it,” Pacino says to his players. “You gotta look at the guy next to you. Look into his eyes. Now, I think you’re going to see a guy who will go that inch with you. You’re going to see a guy who will sacrifice himself for this team, because he knows when it comes down to it, you’re going to do the same for him.”

That’s what Romney doesn’t have. It’s not really about an anger deficit. It’s a deficit of battle scars. There is still time for Romney to take back the momentum of this campaign. But he needs to earn back the trust of the conservative movement. He needs to summon February 2008.