The stakes are high in tonight’s Republican presidential debate at the University of Miami. A day before last week’s debate in Detroit, Ben Carson suspended his campaign. Then and again tonight, only four candidates — Donald Trump, Ted Cruz, Marco Rubio and John Kasich share the stage.

With a field far narrower than the original seventeen contenders, there is more time to probe each candidate, with follow-up. In other words, without a litany of intervening attacks and responses, viewers can easily follow the limited discussion and hold a candidate accountable as they hear a rebuttal. Last year this compressed format would have hurt Trump, but he is (only) somewhat better informed; it’s clear that he remains insufficiently briefed. But much of his support now seems firm. He was more vulnerable last year, when The Establishment inexplicably gave him a pass.

Moreover, so many voters are casting ballots by mail that Trump is somewhat insulated from Election Day voters, including the late deciders who have trended against him. So it’s unclear, for example, how much of the Florida vote tonight’s debate can affect, or if any Trump missteps tonight merely set the national stage for other primaries down the road.

So far Trump is like a momentum stock with an energy all its own. But some momentum stocks crash. If you already took your capital gain, it doesn’t matter. But if you’re still holding the stock, then your paper gain has evaporated. The situation with Trump is quite different. At some point down the line, he may have — if not a majority of delegates, a near-majority on the first ballot, which would make depriving him of the nomination difficult, especially under current convention rules designed to favor The Establishment candidate, and now the rules favor The Insurgent, Donald J. Trump.

Tonight’s debate is very important because with so many other candidates gone, a Trump blunder could be magnified. Ted Cruz needs a blowout performance, and Marco Rubio needs it much more. As for Kasich, even if he wins in Ohio, for him to be nominated in an open convention beyond the first ballot, the Republican National Committee would have to change the rules, and Trump is now preparing contingency plans for any rules change that could enable the kind of open convention that could thwart his nomination if he falls short of a majority of delegates on the first ballot.

Tonight you can expect specific questions on policy, and Trump needs to be presidential, no easy task for the combative and aggressive candidate. CNN’s Jake Tapper, who as ABC White House correspondent regularly challenged the Obama White House, will likely concentrate on inconsistencies, especially Trump’s. His CNN colleague Dana Bash will focus on politics and power and whether Trump can work with Congress. Salem’s Hugh Hewitt, ever professorial, will pursue esoteric questions, at least one of which will stump, and therefore provoke Trump. If the others don’t ask the income tax return question, Hugh will. And the Washington Times’ Stephen Dinan will emphasize national security, particularly that Trump cannot bully generals into illegal orders; Trump will say the issue is settled, and Dinan will press similar foreign policy matters, and ask Trump how he can be neutral in the Mideast if Israel is our ally. On ISIS and using force, Trump has an ingenious way of responding to specifics: “I don’t want to telegraph to the enemy what I will do. We’ll just hit them.”

In the last couple of days Trump has moderated. His more positive demeanor may be based on his own instinct. After all, sycophants around Trump are afraid to challenge him. And his youngish surrogates on cable defend him in robotic monotone. Perhaps Trump finally has found a few adults (maybe Ivanka) with the status and fortitude to advise him to clean up his act. If not now, when? Contrary to mythology, the primary and general elections are not discrete, and Trump’s insults and mistakes can harden an anti-Trump bloc for the general election. His equivocation on a summary condemnation of the Ku Klux Klan was preposterous and scary.

As it was, Trump in his Tuesday night victory talk was surrounded by his golf club members and, beyond that, the press corps that Trump treated more respectfully than in the past. He had a series of Trump products on display, everything except a Trump Ginzu knife, in what at times appeared to be an Infomercial on Home Shopping Network. While his victory “speech” was unorthodox, so was his modus operandi of taking questions. For nearly an hour he dominated live national television. It was another coup for him.

Trump’s problem with sound bites is that he has too many. So he walks all over lines; it’s unclear whether he wants the story lead to be, “Trump calls on ‘Little Marco’ to drop out” or something else. About Trump University: “I don’t settle lawsuits. The lawyers learn, they don’t sue you.” In the past he keeps dismissing the lawsuits against him as just “a civil lawsuit,” not a criminal action for fraud. But that’s not the issue, just like eminent domain for highways was not the issue when his opponents faulted him for using eminent domain to seize a woman’s home, the land to be used for a valet parking lot for high-end gamblers in Atlantic City.

And about the negative campaign against him: “I want to thank the special interests and the lobbyists… to raise that much money that quickly.” His opposition has been so inept he can ridicule it.

Defending his plurality support among evangelicals, Trump returned to a familiar theme of defending Christmas. “They’re chipping away at Christianity… I’ll be the best thing that ever happened to evangelicals.”

The closest he came, in Tuesday night’s victory talk, to being negative was responding to Sen. Lindsey Graham’s attack. “Every single person who has attacked me has gone down,” Trump observed before downplaying Graham, who “has been fighting a war for 15 years.”

“Politicians will never get you to the promised land,” noted Trump in an unusual Biblical allusion, and then he had this to say about Marco Rubio: “Hostility works for some people, not for him.” Trump is right. Rubio, a man of intelligence and intellect, hurt his brand by going down to Trump’s level.

Trump often returns to his various themes, a central postulate being that his efficient and cost-effective campaign anticipates his presidency: “Wouldn’t it be nice if we had a country that worked that way?”

“Mitt was very vicious,” Trump said, as if Trump himself is above the fray. But Trump connected with the electorate: “I wish he used that same energy against Obama. He would have won.”

Improbable as it sounds, Trump continues to insist, “I am a unifier.” Expect these kinds of quotes above and this sort of approach tonight, along with: “We have something special going on in the Republican Party. The elites don’t respect it.”

Trump stays on message. The new Trump we saw on Tuesday night likely previewed his stance tonight. With his now familiar, “I’m a common sense conservative,” Trump talks in crisp self-supporting sentences: “We’re going to pay off debt… I am a free trader, but I’m a smart trader.” He runs through a raw meat list for the conservative base he needs — support the military (“no one will mess with us”), help the veterans (“these are good people, and we’re not helping them”), secure the border (“we’re going to be a country again”), and end Common Core (“a total disaster”). Further, for dessert: “My sons and I are members of the NRA.”

“Our veterans are treated worse than how we treat illegal immigrants,” is a marvelous Trump sound bite. Within seconds, he is off to other topics, such as how much we spend on education, and how ineffective our educational system is. “It’s not going to happen any more.” Trump is most effective at brilliantly stating problems and hitting the opposition simultaneously. 

In sum, after his victories on Tuesday in Mississippi, Michigan, and Hawaii (“I hope Republicans will embrace it. We have Democrats and independents coming over”), Trump tonight will open with unity: “We should grab each other. We should unify the party…. Let’s come together, folks. We’re going to win… I’m a unifier. I get along with people.” He’s not even close to a majority of delegates, but he’s trying to depict his opposition as spoilers, and he’ll do that tonight.

Ted Cruz and Marco Rubio obviously will focus on Trump. Cruz knows he can’t win Florida, but he wants to deprive Rubio of any chance to win, because his (Cruz’s) pitch now is it’s a two man race. Rubio must win Florida, and that means challenging Trump tonight, and in a different way than matching insults. Rubio’s handlers never perfected his delivery to slow him down. John Kasich will continue to play out his hand, as the serious candidate who does not deal in personalities or personal issues. All of Trump’s work-in-progress transition to presidential mode can go out the window if he (Trump) responds in kind to an attack and things go downhill from there. “You’re getting nasty,” Trump will say before going downhill.

If The Establishment were competent, it would probably want a Kasich (Ohio) Rubio (Florida) ticket for expediency. 

At the debate last Thursday Trump doubled down on a major blunder, his advocacy of going after family members of terrorists. After Gen. Michael Hayden, who headed the National Security Agency, had pointed out that the military would refuse to carry out illegal orders from their commander in chief, Trump said in the debate that his leadership would be enforcing his will on them. The next day, with a rare prepared statement, the Trump campaign disowned Trump’s position in the debate: by saying that Trump understands “that the United States is bound by laws and treaties,” and that he would “not order our military or other officials to violate those laws and will seek their advice on such matters. I will not order a military officer to disobey the law. It is clear that as president I will be bound by laws just like all Americans and I will meet those responsibilities.”

Trump says the debates are getting boring, but that’s partly because the other candidates are repetitive and Trump himself says the same things. There is little continuity. Last year Trump did not know about the nuclear triad (bombers, land-based missiles, submarine-based missiles). It’s hardly ever mentioned again. Hewitt may reprise it tonight.

It is possible that Trump may continue to make mistakes in debates. But they do not affect his base, which hardens the longer time goes on. Other candidates flail at him, but there is no cohesive strategy to go at why voters support him. Without a coordinated free/earned media and a paid/advertising media that involve real people, Trump may continue to lose points in tonight’s debate and yet “win the debate.” That’s because the opposition has been unable to question Trump’s judgment and temperament effectively; Trump so far has parried the attack with “They’re chopping off heads, and you don’t like my tone.”

Meanwhile the Stop Trump movement has played into his hands, and you can expect Trump to talk about recent developments. For example, on March 7 Huffington Post reported on a “secretive meeting” with “billionaires, tech CEOs and top members of the Republican establishment [who] flew to a private island resort” to conspire on stopping Trump. This group of powerful and wealthy heavyweights, but politically incompetent, does not understand that to stop Trump you need to co-opt his issues — that was last year’s undone chore. Most of all, to stop a populist, you need other populists, not Establishment Titans from Central Casting holding publicized Secret Meetings.