“I recognize that Donald is dismayed that his poll numbers are falling in Iowa. But the facts and the law here are really quite clear. Under longstanding U.S. law, the child of a U.S. citizen born abroad is a natural-born citizen,” Cruz, who was standing directly to Trump’s left, said. “Not too many years ago, Donald did a long interview with Tim Russert. And in that interview, he explained his views on a whole host of issues that were very, very different from the views he’s describing now. And his explanation — he said, ‘look, I’m from New York, that’s what we believe in New York. Those aren’t Iowa values, but this is what we believe in New York.'”

The highly anticipated brawl between Cruz and Trump marked and escalation in their battle for Iowa — they are virtually tied in the race for the Feb. 1 caucuses — and constitued the first time the bombastic billionaire has sustained a potentially damaging body blow to his frontrunner status in the Republican primary. Trump leads most state and national polls; Cruz runs second, followed by Rubio. The other four candidates that made the prime time stage in the North Charleston Coliseum and Performing Arts Center are fighting to emerge from the second tier.

Cruz’s hits on Trump could change the contours of the heated competition for GOP caucus goers in Iowa. But the New Yorker didn’t necessarily have a horrible night. He excelled when the moderators steered the debate into a discussion about taxes and trade, displaying a sophisticated command of these issues that he had not shown in the previous five televised events. And Trump managed to undercut Cruz’ attack on his “New York values,” which has been carefully calibrated to diminish his standing with heartland conservatives, by framing the issue about how the city responded to the Sept. 11, 2001 terrorist attacks.

And, Trump managed to do so with a soft, heartfelt touch, and absent his usual vindictiveness. “When the World Trade Center came down, I saw something that no place on Earth could have handled more beautifully, more humanely than New York,” he said. “You had two 110-story buildings come crashing down. I saw them come down. Thousands of people killed, and the cleanup started the next day, and it was the most horrific cleanup, probably in the history of doing this, and in construction. I was down there, and I’ve never seen anything like it.”

Rubio was expected to be the main target heading into the debate, having sustained daily attacks on the campaign trail for the last several weeks from Bush, Christie, Cruz and the super PACs supporting their candidacies (Rubio’s super PAC has been attacking Christie on the air as well.) But that didn’t turn out to be the case, allowing Rubio to go on offense and deal separately with Christie and Cruz — and even instigate an argument with Trump over trade. If Rubio’s attack on Christie looked a little shakey, he could at least feel comfortable that he bested the articulate New Jerseyan on the issues.

Goaded by the moderators, Rubio took Christie to task for his previous support of Planned Parenthood, which runs abortion clinics, for supporting the confirmation of liberal Supreme Court Justice Sonia Sotomayor, who was nominated by President Obama; and for his past support of Commmon Core education reforms, a policy that is particularly opposed by conservatives. But Rubio’s deliberate critique of Cruz’ tax reform plan, over it’s inclusion of what the Floridian insists is a “value added tax” — Cruz says that’s not true — as well as when he highlighted the Texan’s recent shifts on issues, including immigration and trade.

“Ted Cruz, you used to say you supported doubling the number of green cards, now you say that you’re against it. You used to support a 500 percent increase in the number of guest workers, now you say that you’re against it. You used to support legalizing people that were here illegally, now you say you’re against it. You used to say that you were in favor of birthright citizenship, now you say that you are against it,” Rubio said.

“And by the way,” Rubio added. “It’s not just on immigration, you used to support TPA, now you say you’re against it. I saw you on the Senate floor flip your vote on crop insurance because they told you it would help you in Iowa, and last week, we all saw you flip your vote on ethanol in Iowa for the same reason. That is not consistent conservatism, that is political calculation.”

Cruz responded: “I appreciate your dumping your opp research folder on the debate stage.” To which Rubio retorted: “No, it’s your record.”

None of the seven candidates necessarily had an obviously poor night, and all professed to accomplish exactly what they set out to do. But outside of the top three, Christie seemed to do himself the most good. He battled aggressively with Rubio and made an articulate case for reforming entitlement programs and strengthening U.S. leadership around the globe. Christie also delivered some of his trademark one-liners that are sure to catch the attention of the political press, not an altogether bad thing for a candidate that needs a breakthrough result in one of the first four February primary contests.

“Lots of people will say lots of different things about me in this campaign and others, but the one thing they’ve never said about me is that I’m misunderstood,” Christie said as the debate opened. “And so when we talk to our allies and we give them our word, in a Christie administration, they know we’re going to keep it.”