“Assume the position!” CNN’s John King ordered the candidates as they approached their lecterns just before airtime for Monday night’s debate.

The Republican presidential contenders did as the moderator told them.

Mitt Romney assumed the position of the capable but cautious frontrunner.

Tim Pawlenty assumed the position of a timid challenger, afraid to take on the leader.

Newt Gingrich assumed the position of a bored college professor.

Ron Paul and Herman Cain assumed all sorts of positions – privatizing Social Security? Loyalty tests for Muslims who want to serve in government? – while Rick Santorum assumed he could get by reciting platitudes.

There was one candidate who rose above the usual positioning, though she stood a head shorter than the six men on the stage. Eleven minutes into the debate, Michele Bachmann stole the show, and she didn’t return it in the subsequent hour and 49 minutes.

“I just want to make an announcement,” she said when asked her first question. “I filed today my paperwork to seek the office of the presidency of the United States. . . . So I wanted you to be the first to know.”

It was a transparent gimmick – Bachmann had previously left no doubt that she would be running – but it was one of several attention-grabbing moments that allowed the back-bench congresswoman from Minnesota to stand out from the pack.

King treated viewers to a peculiar game, asking each candidate a “this or that” question. Does Bachmann favor Elvis or Johnny Cash? (Answer: both.) Does Santorum prefer Leno or Conan? (Neither.) Further questioning revealed that Pawlenty prefers Coke to Pepsi, Romney likes his wings spicy, Cain enjoys deep-dish pizza, and Paul prefers his BlackBerry to the iPhone.

But really there is only one this-or-that question of importance: Romney, or somebody else? Judging from the polls, Republican voters do not especially want Romney, an unusually weak frontrunner. But as long as six or more rivals are carving up the anti-Romney vote, none has a chance of beating him.

Based on Monday night alone, Bachmann was the one who emerged as the anti-Romney from the otherwise drab field. That is supposed to delight Romney’s advisers, who see her as less viable than the more accomplished Pawlenty. But while Pawlenty on Monday was canned and meek – he doggedly resisted repeating his earlier “Obamneycare” criticism of Romney – Bachmann displayed a powerful appeal to the Tea-Party types who dominate Republican primaries.

She served Tea Partyers all their favorites: “I want to announce tonight President Obama is a one-term president. . . . I will not rest until I repeal Obamacare. . . . There is no other agency like the EPA. It should really be renamed the job-killing organization of America. . . . I fought behind closed doors against my own party on TARP.”

Actually, Bachmann didn’t have much of a role in the Troubled Asset Relief Program, but nobody was keeping score. They were too busy counting kids. “I have five sons. . . 16 grandkids,” Romney reported.

“Karen and I are the parents of seven,” Santorum boasted.

“I’m the father of two,” said Pawlenty.

“Father of two, grandfather of three,” contributed Cain.

But none could compete with Bachmann: “I’ve had five children, and we are the proud foster parents of 23 great children.” She mentioned that last statistic twice more during the debate.

Bachmann didn’t look into the wrong camera this time, or botch any more Revolutionary War stories. She did say that as president she would “confer with our commanders-in-chief” about the service of gays in the military. And she did contradict herself when she proclaimed that she would not interfere with state laws on marriage but a moment later said she would support a constitutional amendment that would do just that. Even that, though, wasn’t quite as painful as Romney’s wish to hand Afghanistan “over to the Taliban military” before revising that to “Afghan military.”

The scene in the “spin room” after the debate told the story of her triumph. For the first 25 minutes, there were no campaign surrogates in evidence from the Gingrich campaign (after last week’s staff mutiny, his two main surrogates were his daughters, who thought he was “great.”) Same with the Pawlenty campaign, which finally produced campaign manager Nick Ayers (who complained about the moderator’s questions on “Obamneycare,” claiming “CNN, for ratings purposes, wanted a good spat to report on.”).

Romney’s surrogates were trying to find news in their candidate’s make-no-news performance (“he won over a lot of voters in New Hampshire when he announced the Bruins were ahead,” said state Sen. Jeb Bradley).

But more reporters were crowding around Bachmann’s advisers. “We saw the entrance this evening of a candidate who deserves to be here,” Republican pollster Ed Goeas announced. “When you wake up tomorrow morning. . . you’re going to find out Michele Bachmann is driving the debate.”

For one night, at least, that was true.