After a full season of debates, all the Republican candidates were in fine fighting trim in the final showdown before the Iowa caucuses. Almost everyone had a strong night, with the exception of Ron Paul, who may have finally gone too far on foreign policy.

Full disclosure: National Review, where I am editor, has an editorial out with our evaluation of the candidates so far, it is especially tough on Newt Gingrich. But I'll do my best here to analyze the debate dispassionately.

Gingrich had center stage and took the first questions. He showed he can be dazzling, as in his smash, jam-packed, eloquent, original, historically well-informed answer on out-of-control judges. Gingrich has been at his best when he agrees with the other candidates, and so it was tonight--when Newt is positive, it takes some of the edge off his sharp personality. He had a self-deprecating reference to his reputation for incendiary words, saying he was "self-editing" before launching into one anti-Obama answer.

He had his worst moments playing defense on taking money from Freddie Mac. At one point, he seemed to suggest he was so well-off that the $1.6 million didn't mean much to him, therefore he wasn't influenced by the cash. He danced around adeptly both on the payments in particular and on his support for the concept of government-sponsored enterprises in general but every one of his answers was greeted with proverbial crickets by the audience.

Michele Bachmann was relentless going after Gingrich and Paul. She has perfected her role of chief prosecutor of the debates. She's fearless and comfortable on the attack.

She clearly bothers Gingrich. He looked incredulous and a little contemptuous during the split-screen when she was after him. He verged on letting too much of his disdain show, but stayed on the right side of the line.

Ron Paul didn't. In an extended discussion of foreign policy, he seemed crankier than ever. He went far out on the limb in condemning the Iraq war ("useless"; killed "a million" Iraqis) and in making excuses for the Iranian nuclear program.

Paul has very committed supporters, but if he's going to win Iowa, he presumably needs to get some marginal voters, too. He may have given them second thoughts, even as he has been accepted into the Republican family during the course of the primary season in a way that would have seemed unimaginable back in 2008.

Romney started out slow and ended up on defense in a discussion of his flip-flops, but in the main was back to form after seeming rattled in the last debate. He's at his worst when he gets frantic when challenged (putting his hand on Rick Perry's shoulder; offering a $10,000 bet) and at his best when he stays in control and elevates. He did that often and had one of the best lines of the night hitting the president for accepting American decline.

Perry had his most impressive debate yet. He was a little shaky in an answer about how he'd do debating the president should he get the nomination and didn't win any points defending business subsidies at the state level. Otherwise, he avoided stumbles, was likable, and effectively got across his message of reforming Washington and diminishing its power. He’s an evangelical version of Senator Lamar Alexander, who ran a populist, anti-Congress presidential campaign in the 1990s.

Santorum, too, was at his best Thursday night. He has suffered in past debates from appearing too desperate to get air time. A little more relaxed, he exuded more authority.

He continues to speak convincingly to bread-and-butter economic issues like the decline of manufacturing, while offering a consistent and forceful social conservatism. In theory, this should play in Iowa, but the theory hasn’t yet been borne out.

Huntsman also may have had his top performance, but that still might not be enough to get a pulse. He has what should be an appealing governing record and agenda, but has been hobbled by his horrible marketing and his persistent lack of pizzazz.

The latest polls have shown the candidates in Iowa bunched up in a highly volatile race. Their last turn on the debate stage before the caucuses won't change that. Get ready for high drama in the Hawkeye state.

Rich Lowry is editor of The National Review and a syndicated columnist. He is a Fox News contributor.