ANALYSIS: Republican Debate Shows What Donald Trump Has Already Won The sixth GOP debate revealed the extent to which Trump has already won.

 -- Donald Trump may yet lose the Republican presidential nomination, and Thursday night’s debate offered hints of the fights that could make that possible.

But the first GOP debate of 2016 revealed the extent to which Trump has already won.

The slow-starting evening focused, for a change, on candidates not named Trump. It seemed to involve fewer than even the smallest-of-the-cycle debate field of seven.

Yet when the candidates engaged with each other, they did so on terms Trump set. His chief rival in Iowa forced to respond to spurious doubts Trump has raised about whether Ted Cruz is even eligible to be president.

“There’s a big overhang – there’s a big question mark on your head,” Trump told Cruz.

Cruz seemed to get the better of the exchange, with Cruz noting that Trump last fall said he no longer thought Cruz’s birth in Canada was disqualifying.

“Since September, the Constitution hasn’t changed. But the poll numbers have,” Cruz said.

But the fact that that Cruz answered those questions at all was a testament to Trump’s ability to dominate the conversation in the race, as he’s done from virtually the moment he entered the race. Talking about Cruz’s birth was Trump’s idea –- his insertion into the political conversation, dominating again.

Cruz, moreover, dropped his strategy of non-aggression with Trump, fleshing out his critique of Trump as embodying “New York values.”

“Everyone understands that the values in New York City are socially liberal, or pro-abortion or pro-gay marriage,” Cruz said. “Not a lot of conservatives come out of Manhattan. I’m just saying.”

It allowed Trump to get serious, at least for a moment.

“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,” Trump said, drawing a few claps, and a slight smirk, from Cruz. “That was a very insulting statement that Ted made.”

There was some tangling further away from center stage. Marco Rubio locked horns with Chris Christie, with Rubio calling Christie a supporter of President Obama’s policies, and Christie labeling Rubio a do-little senator.

Rubio and Cruz engaged more directly than they have to date, with charges of flip-flopping on immigration and national-security matters forming the basis of a fight that might benefit, among others, Trump.

Mostly, the candidates were back to long-discarded strategies that didn’t involve attacking the man at center stage. Jeb Bush called Trump’s proposed Muslim ban “an unhinged thing,” but Cruz and Rubio spent more time explaining why it had appeal than saying why it’s an idea they oppose.

Bush and John Kasich, who both tried out attack-Trump strategies at earlier debates, were mostly back to touting their gubernatorial leadership. All the candidates, of course, spent significant time attacking Barack Obama and Hillary Clinton – some of them sounding outright Trumpian in doing so.

“This guy’s a petulant child,” Christie said of the president. “We are going to kick your rear end out of the White House, come this fall.”

“The simple fact is the world has been torn asunder,” said Bush.

“Hillary Clinton is disqualified from being commander in chief of the United States,” said Rubio.

Cruz and Trump were the main combatants –- and their battle in Iowa could determine whether Trump can be stopped in the race for the nomination. Cruz may yet beat Trump there, and the establishment still has hopes of a third alternative emerging.

But if Trump loses, he’ll lose in a race with terms he set.

“We have to stop with political correctness,” he said. He drew no argument on that point.