After attending last week's Trump rally in Vermont, I wrote:

It's assumed by the GOP establishment that once the field narrows Trump will bump up against his natural ceiling. I think the opposite is true. Trump has essentially sat out these stupid ten-man TV debates and then resumed his rise once they're over. If it came down to a four- or three- or two-man race, the man I saw on Thursday night would be a formidable debate opponent. And I don't doubt he could hold his own against Hillary.

We got a preview of that last night. Having endured "these stupid ten-man TV debates" for six months, Trump found himself in a seven-man show and for the first time played for the full two hours - and dominated. There are two plausible views of last night's South Carolina ding-dong - either that Trump won, or that it was a Trump/Cruz tie. I incline to the former, but I accept that last night many of the post-game commentariat plumped for the latter.

The Fox Business debate was the best so far, in part because Maria Bartiromo and Neil Cavuto asked interesting questions without any of the look-at-me insecurities that afflict most presidential-debate moderators. But the main reason it was so good was that there were three fewer people than there've been on previous occasions: This may seem hard and somewhat unfair on Rand Paul, Carly Fiorina and Mike Huckabee, but, realistically, none of them is going to be the nominee. Last night was a preview of how the race is going to be in the weeks ahead.

There were two contests going on: the battle between Trump and Cruz for first place in Iowa, and the battle between Rubio and the non-Rubios for top placed "moderate" in New Hampshire. Ben Carson was off in some playground of his own, talking about how we hadn't had a natural solar EMP attack for 155 years, and his eccentricities did not seem to me quite as charming as they were six months ago. He did nothing to arrest his decline. The Trump/Cruz and the Rubio/non-Rubios battles were sealed off from each other for most of the night, excepting Jeb's attacks on Trump from the far edge of the stage to which he now clings, and Rubio's decision to go head-to-head against Cruz.

Trump and Cruz both had good nights, their confidence exemplified by their mutual joshing that each might put the other in the vice-presidential slot. To take them one at a time:

Trump had more strong moments than in any previous debate, including his response to Nikki Haley's State of the Union gift to him: He would, he said, "gladly accept the mantle of anger". His pushback against Ted Cruz on "New York values" was masterful, and a brilliant exploitation of a rare misstep by Cruz. His answer on whether he wanted to rethink his moratorium on Muslim immigration - "No" - was effective, and underlined his disdain for the weaselly evasions of politics. And, after a question on whether he'd put his assets in a blind trust, his reply that as president he wouldn't care about his companies but only about the country was apparently sincere and oddly moving. He also benefits from the fact that these debate-night audiences are stuffed with Republican Party Assistant Deputy County Chair-type apparatchiks who are largely hostile to him: He never looks more serene than when they're booing. From start to finish, Trump had a very good night.

Cruz had the biggest barrage to deal with - from Maria Bartiromo on his Goldman Sachs loan, from Trump on his eligibility for the presidency, and finally from Marco Rubio on his voting record. The effect of all this was that he was having to think on his feet and thus seemed less canned than he sometimes comes over as. It was a fine performance. However, the "New York values" exchange was a clear defeat for him, and it's worth remembering how he got into the mess a couple of days back: He'd been asked about Trump beginning his Iowa rallies with "Born In The USA" (which is a pretty droll and effective jest) and Cruz responded that maybe he should open with "New York, New York" (which is neither so droll nor effective) - and it illustrates how the eligibility question can throw him off his game.

After the debate, the analysts and experts all agreed that Cruz had won the exchange with Trump on whether he meets the qualifications to run for president. I think he "won" in the same sense that Carly Fiorina "won" the exchange with Trump about her face - when emasculation fetishist Rich Lowry asserted that she'd "cut off his balls". She hadn't - which is why yesterday she was back on the kiddie table eating crow balls. Pundits, who make their living by saying clever things, assume that debaters' points translate into victory in the real world. Trump, by contrast, keeps his eye on the larger issue - which in this case is that Cruz can't win as long as we're talking about this subject:

The poll finds that the 'birther issue' has the potential to really hurt Ted Cruz. Only 32% of Iowa Republicans think someone born in another country should be allowed to serve as President, to 47% who think such a person shouldn't be allowed to serve as President. Among that segment of the Republican electorate who don't think someone foreign born should be able to be President, Trump is crushing Cruz 40/14. Despite all the attention to this issue in the last week, still only 46% of Iowa Republicans are aware that Cruz was not born in the United States. In fact, there are more GOP voters in the state who think Cruz (34%) was born in the United States than think Barack Obama (28%) was. Donald Trump knows what he's doing when he repeatedly brings up this issue- 36% of Cruz voters aren't aware yet that he wasn't born in the United States, and 24% of Cruz voters say someone born outside the country shouldn't be allowed to be President.

Let me say at the outset that I like Ted Cruz personally, I agree with him on most of the issues, I side with him on his differences with his fellow Republican senators, and I think he would make a fine president. In addition, unlike most of my fellow pundits, I know where he's coming from - literally: I too was born in Canada to a non-Canadian mother. So it pains me to have to say that I don't agree that the eligibility question is the thoroughly "settled law" that he thinks it is: Were he to be the nominee, it's entirely likely that Democrats, not to mention the GOP establishment that loathes him with a pathological intensity, would file suit somewhere, and, unlike the Obama cases, not have much difficulty finding some leftie judge willing to entertain the issue. [UPDATE: First lawsuit filed.] Perhaps at the Supreme Court some brilliant Ivy League constitutional lawyer will win the day for him.

But that's not the point. As that poll lays out, most Iowans are not aware that Cruz was born in Canada and, when it's pointed out to them, most Republicans think it's a disqualifier. Trump's pitch is artful: "Me, I got no problem with my good friend Ted being Canadian - they're lovely people, I employ a lot of them - but I'm just saying these Democrats feel differently and they're very litigious..." And that line is potentially lethal. Speaking as a guy who gets told to bugger off back to Canada all the time, I note the above front page from today's Daily News:

DROP DEAD, TED

Hey, Cruz: You don't like NY values? Go back to Canada!

That's how much he "won" the eligibility issue. "Go back to Canada" is now a front-page refrain.

Over to the mod squad. Again one by one:

I don't think Marco Rubio had a good night. Everyone talks about him as a "top tier" candidate, but, to be boringly pedantic about it, he's not. Poll-wise, he's stalled in the ten-to-twelve per cent range - and he didn't do anything last night to raise his ceiling. If "authenticity" is the issue (and, in their varying ways, Trump, Christie, Kasich, Carson and Cruz are all authentic), Rubio is the guy who always sounds like he's defaulting to the relevant passage of his stump speech. Most times the cute lines are a little too cutely delivered, but last night he tripped himself up: He was trying to say that Obama cares less about investing in the US military than in Planned Parenthood, but it took him three runs at it to get the line to come out right. I didn't think it worth the effort myself. Half-an-hour after the debate ended, one of Rubio's campaign ads popped up, and he delivered the military/Planned Parenthood shtick perfectly. But that's the problem: Every answer sounds like "Here's one I made earlier."

That leaves an opening for a non-Rubio to snaffle the "moderate" vote away from him. Who will it be?

Not Jeb. You could find commentators willing to argue that he had his least worst night by his own abysmal standards, but at this stage that isn't going to be enough. Aside from anything else, for a hundred million bucks you'd think Mike Murphy and all the smart guys could find someone to teach Bush to stand in a more presidential way - to adopt a posture that communicates authority, confidence, etc, rather than his sad-sack kick-me stance. All night long, he was keen to pick fights with Trump - not because he's foolish enough to think he can hurt the frontrunner, but because his strategy to winning the moderate primary is to show that, unlike Christie, Kasich and Rubio, he's got the cojones to take on the big guy. Unfortunately, every time he picked a fight, he'd wind up throwing only feeble tentative jabs - for example, inviting Trump to "reconsider" his position on banning all Muslims. Jeb picking a fight reminds me of that "Looney Tunes" where Daffy Duck is trying to do the same with the tough hombres in a western saloon and finally asks: "Anyone for tennis?" And he had no answer to the question that, if Trump is "unhinged" for wanting to end Muslim immigration, are all those South Carolinians who support him on that likewise "unhinged"?

Anyone for Jeb? Well, he finally won that coveted Lindsey Graham endorsement. Otherwise, Bush did nothing to arrest his grim death spiral.

Chris Christie had a goodish night - not quite as good as before, and making allowances for the fact that certain things he said seem to be not true. But, if you're looking for a fellow who stands on moderate turf butchly, he does a better job than Jeb.

John Kasich had pressed his suit and was in reasonably affable mood. He's not as good as Christie on TV, but he's good on the stump. He persists in talking up his experience in Washington and Ohio in a season when the voters' contempt for political experience is the most salient fact of the race. So he must have figured, notwithstanding Trump, Cruz, Carson et al, that there's room for one I've-been-there insider campaign. Given Rubio's underperformance, there's probably a fourth ticket out of the Granite State: Trump, Cruz, Rubio - plus either Christie or Kasich. The latest New Hampshire poll has Kasich tied with Cruz in second place, with Rubio back in fourth. If that were to hold on primary night, Marco would be severely wounded, and perhaps fatally.

So that's how things stand. What can stop Trump? Experts think he has no ground game in Iowa and his numbers are soft and reliant on political neophytes who have no idea of the degree of commitment a caucus requires. If that's true, he'll come a bad third or worse in the Hawkeye State, and, in the week before New Hampshire, slip sufficiently to enable someone to steal the Granite State away from him. But that conventional wisdom might be as wrong as the last six months' worth of conventional wisdom. And, absent that, this thing is his to lose.

What can stop Cruz? A bad loss in Iowa would be a severe setback, because he has minimal chance of winning New Hampshire. On the other hand, a narrow Cruz loss in Iowa would probably persuade Trump to rekindle their six-month bromance and put "Go back to Canada" on the back burner.

So the great winnowing is under way: Trump, Cruz, Rubio plus Kasich or Christie.

PS In case you missed it, here's me and various Vermonters captured for posterity at the Trump rally last week. Eva Sollberger of the "alternative" weekly Seven Days asked me and the locals for a few words for her "Stuck In Vermont" video. Non-North Country types seem to have enjoyed my plaid coat: