Fresh from his first-ever election -- and his first-ever political loss -- the billionaire now faces pressure to show that his runner-up-spot in the Iowa caucuses was an aberration shaped by the unique politics of a state that was always stacked against him and is not a symptom of fundamental flaws in his entire campaign.
It will be a mission that will unfold over the next week in New Hampshire, where Trump holds a commanding lead. And it will take place against a suddenly intense subplot of the GOP presidential race, a looming establishment bloodbath advanced by Marco Rubio's late sprint to a strong third in Iowa.
A mellow, disciplined Trump appeared in New Hampshire on Tuesday evening and declined to take the bait as reporters repeatedly tried to lure him into criticism of Iowa voters or to accept that his campaign had suffered a blow. He said he hoped to win the Granite State primary next Tuesday but did not feel any extra pressure because of what happened in Iowa on Monday.
"I think we did really well. I think we had a very good result," Trump said, insisting that he still loved the people of Iowa, though did allow that his second place spot "could have been a little bit better."
But he professed to be mystified that the late surge that lifted Rubio in Iowa was being billed by the media as a huge success, while his showing was being portrayed as a disappointment.
"People didn't talk about my second place," Trump said. "People didn't talk about it as positively as they should have," the former reality star said, insisting that he did "okay" and "very well" in Iowa.
Trump had earlier also weighed into the post-mortem over the caucuses on Twitter, accusing the media of biased coverage of the caucuses.
"The media has not covered my long-shot great finish in Iowa fairly. Brought in record voters and got second highest vote total in history!" Trump tweeted.
Victim of his own success
In some ways, Trump was a victim of his own success. By overtaking Cruz in polls in the final days before the caucuses, he set himself up for a blow in the expectations game that is as important as the results in Iowa.
Had he slowly built toward a second-place finish to Cruz — poised to win Iowa based on his impeccable credentials among evangelical and social conservatives so important in the state — perceptions of his result would have been much more favorable.
Of course, losing Iowa is hardly a death blow for GOP candidates. Only two of the last six winners of the GOP caucuses went on to become president.
And as Trump noted, he enjoys a huge lead with only a week to go before the New Hampshire primary.
In the latest CNN Poll of Polls, Trump led Cruz 31% to 13% with Rubio, who will now be looking for a post-Iowa boost in New Hampshire, at 11%.
But Trump's wide lead will not insulate him from serious questions about his campaign infrastructure and strategy that it will now take the Granite State to begin sorting out.
Among them: Is it possible that his polling numbers elsewhere are overstating his true level of support, as they did in Iowa? Will the deficiencies in Trump's political operation compared to the Cruz turnout machine in Iowa be repeated in later nominating contests? Was Iowa just a special case, or is Trump's insistence on running a rule-breaking campaign based almost entirely on the buzz he earns from dominating the news media a strategy that will eventually bring him down?
It could be that Iowa's use of a caucus system exacerbated Trump's organizational deficits and that the easier voting process of a primary may make turnout muscle less important going forward.
But he may also be forced to rethink the frugal nature of his advertising spending, that has been the subject of his frequent boasts on the stump, if his rivals and establishment Super PACs smell weakness after Iowa and launch fierce new attacks against him.
Rubio's stronger than-expected showing in Iowa added up to the best morning of his campaign for the Florida senator, who landed in New Hampshire with a big smile on his face in the early hours of Tuesday.
Rubio has been something of a mystery in the 2016 campaign, given that his generational appeal, aspirational tone and sparkling rhetorical skills seem to position him as an ideal foil for the darker narratives pushed by Trump and Cruz and an ideal champion for the beleaguered GOP establishment.
So far, though, despite a string of good debate performances and his well-timed surge in Iowa, Rubio still does not lead the polls in any early voting state, prompting critics to wonder where he can win.
It did not take long for Rubio's establishment rivals -- whose attacks have extra bite because they are facing a New Hampshire or bust scenario, to welcome him to the top tier.
"It's time for him to man up and step up and stop letting all of his handlers write his speeches and handle him, because that's what they do, that's what you have to do for somebody has never done anything in their life," New Jersey Gov. Chris Christie said on Tuesday.
"Let's get the boy in the bubble out of the bubble and let's see him play for the next week in New Hampshire. I'm ready to play. I hope he is because I'll be ready to see him on stage on Saturday night."
Christie's unsubtle attempt to rough up Rubio with brusque New Jersey street politics points to what is likely to be a full frontal assault on the Florida senator in Saturday's night's GOP debate.
Rubio's one-time mentor, former Florida Gov. Jeb Bush, who barely registered in Iowa and is desperate for a breakout moment in New Hampshire, seemed to sense the political winds even while the voters were being counted Monday night.
After claiming that Trump was running a campaign based on little more than insults, Bush went on to imply that Rubio and Cruz were "backbenchers that have never done anything of consequence in their lives."
"They are gifted beyond belief. They can give a great speech," Bush said. "But I think it's time for us to recognize that maybe what we need is someone who can lead."
Christie's prediction will surely hold up: Rubio is in for an "interesting week."