Everyone stepped up their game for Tuesday’s Republican debate in Las Vegas. Even Gov. Rick Perry (Tx.) was energetic and feisty on the stage — for a bit. But the winners were the acknowledged frontrunners, former Gov. Mitt Romney (Mass.) and Herman Cain.

The first 25 minutes or so put Cain and his “9-9-9” plan in the crosshairs. Everyone piled on, and he did his best to defend his questionable plan that has a slew of critics on the right and the left. Newt Gingrich threw him a lifeline of sorts by saying Cain’s plan was more complicated than its simplistic moniker (or the author’s explanations) would have you believe. And if you go to the “9-9-9” page on Cain’s website, there isn’t a whole lot of specificity. Still, that he didn’t crumble, back away or repudiate any of his questionable tax plan under such intense scrutiny makes him a winner. For now, at least.

Once they were done picking apart Cain and “9-9-9,” the candidates turned their attention to Romney and everything else. From health care to immigration, Romney came under fire. The most dramatic moment of the debate was a direct, personal attack by Perry on Romney and his hiring of illegal immigrants on his property. It could have been devastating. But as Romney showed in this debate and every gathering since Perry got into the race, he’s ready to smack back.

As for Perry, the only thing that made him look comatose was his make-up. He looked like he walked through a cloud of flour on the way out to the stage. But that didn’t cover up a noticeable vigor in his performance. A vigor, alas, that didn’t last. When the question of religion and the foul statements by Rev. Robert Jeffress came up, Perry was tongue-tied. His answer weak. That energy we saw in hour one was pretty much gone by the end of the debate.

While Romney played the scold, shhshing Perry and Rick Santorum (on health care) as they tried to talk over him, it wasn’t enough to turn the crowd on him. Not like they did on Perry. His high point was that low-blow attack on Romney on illegal immigration. It was a low-blow attack because Perry kept coming back at it long after the initial awe at his audacity faded into boos from the audience. And I have to say, Santorum gave a polished answer on the question of whether religion should be a factor in choosing a president. It should be based on values, he said.

Ron Paul, Newt Gingrich and Michele Bachmann all gave the performances of their lives, but it wasn’t enough to shake them out of their second-tier status. We’ll see how Perry’s immigration swat at Romney plays over the next 12 hours. But my hunch is that no one’s dropping out after this debate, which is pretty remarkable.