(Update: This post is also available as a web-only article here.) This afternoon's Republican debate in Dearborn, Michigan went pretty much the way the entire campaign has gone lately: A lot of hype about Fred Thompson, but ultimately a contest between Rudy Giuliani and Mitt Romney. The debate seemed to pass Thompson by. He looked unsteady on his very first response--pausing awkwardly during a riff about the economy--and improved only marginally as the afternoon wore on. Later, Thompson mangled a question about the falling dollar, appearing uncertain as to why the development might be bad. His most cringe-inducing moment came when Maria Bartiromo talked him up as a Social Security wonk. "Senator Thompson, you seem to be one of the few that is willing to ... give specific steps to maintain the long-term solvency of Social Security. Describe some of those specific steps." Thompson filibustered for a minute or two in vague and sometimes bizarre terms--"growing the economy," "bridges and infrastructure," "let people provide for some of their own savings"--before recalling that he supported indexing Social Security benefits to inflation. Thompson will certainly live to fight another day. He parried the most overt gotcha of the afternoon by successfully naming the prime minister of Canada. (Though afterward he looked much too relieved for having cleared what was a pretty minimal bar.) And he committed no outright gaffes. This seems to be why several conservative bloggers crowned him today's "winner." But there's a lot of territory between surviving and actually competing, and it's not yet clear Thompson can do the latter. The moment that distilled this for me came at the end of an answer about Iraq, when Thompson quipped that "the average 20-year-old serving us in Iraq knows more about what it takes for our national security than the average 20-year veteran on Capitol Hill." It was a little forced, but hardly a terrible line. Still, the way Chris Matthews said "thank you" when he'd finished seemed both incredibly patronizing and yet somehow appropriate. There's more to running for president than unfurling one-liners. For their part, Romney and Giuliani continued the back and forth they've waged via press-release this last week. Romney accused Rudy of challenging the line-item veto "all the way to the Supreme Court" and of fighting to retain New York City's commuter tax. Rudy, in turn, insisted he was a certified tax-cutter and that Romney was the free spender of the group. As for the line-item veto, Rudy saw it, somewhat counter-intuitively, as yet another opportunity to tout his anti-Clinton credentials. "I took President Clinton to court [over the line-item veto] and I beat him," Rudy said. "And I don't think it's a bad idea to have a Republican presidential candidate who actually has beat President Clinton at something." (Would scrabble count? Rock-scissors-paper?) If Romney's decision to seize on the commuter tax sounds a little small-bore, particularly alongside the long list of grievances conservatives harbor toward Giuliani--well, it is. But there's a rationale: The two men are locked in a death-struggle in New Hampshire, where fiscal issues tend to trump social ones. Giuliani has more or less decided to forfeit Iowa, calculating that Romney's early lead there is too large (the latest Des Moines Register poll shows Romney in first place with 29 percent of the vote, and Rudy in fourth place with 11). The state's large social-conservative population also makes the terrain inhospitable. But because no front-runner can go too many states without competing, and because Giuliani can't afford to let Romney build momentum, he must at least finish a respectable second in New Hampshire. (Polls currently show Romney with a small lead over Giuliani in the state, down from double digits this summer.) The flip side of this calculus, says a Republican strategist not affiliated with any campaign, is that Romney could be finished if Giuliani wins New Hampshire. Many of the states that vote in the multi-primary extravaganza on February 5--Arkansas, Alabama, Georgia, Oklahoma--may be even worse for him than for Rudy, given Southern evangelicals' suspicion of Mormonism. Without the boost Romney would get from a New Hampshire victory, he'll be hard-pressed to take any of the day's bigger (and more moderate) prizes, states like California. And without them, it's hard to see where his delegates come from. If the direct confrontation between the two men today didn't exactly break the New Hampshire stalemate, there were two smaller exchanges that could prove telling. The first arose from a question about whether London might be overtaking New York as the center of international finance, as many on Wall Street fear. At first, Giuliani didn't entirely seem to understand what Bartiromo was asking. He spoke in gauzy generalities about how "London's not going to replace New York." Only after repeated follow-ups did he finally engage, citing the risk of financial-market over-regulation. When Romney fielded the same question, his synapses fired instantly: "Is London going to replace New York? Of course not. Should we fix Sarbanes-Oxley and take out Section 404 as it applies to smaller companies? Of course we should." The man has game. The second useful insight came via the debate's "lightning round," when Matthews asked the second- and third-tier candidates whether they'd support the GOP nominee, whomever he turns out to be. Ron Paul and Tom Tancredo said they wouldn't. Sam Brownback and Duncan Hunter said they would. But both men added what sounded like an implicit threat. As Brownback put it: "I believe that the person that's going to lead the party will be somebody that is pro-growth and pro-life." I wonder who he has in mind? --Noam Scheiber