The need to live up to that image helps explain why Trump, who is under ever-increasing pressure from the Russia investigation, on Wednesday recognized Jerusalem as Israel's capital despite the widely acknowledged risks.
"When I came into office, I promised to look at the world's challenges with open eyes and very fresh thinking," Trump said in the first words of a speech on Wednesday outlining a sharp shift in Israel policy.
"We cannot solve our problems by making the same failed assumptions and repeating the same failed strategies of the past," he said.
He's also lived up to his wider, conceptual promise of being a disruptive force in Washington and around the world. US enemies now lack the comfort of a predictable adversary, as do domestic adversaries -- and allies.
So far, the President has not paid a tangible price for living up to his most controversial promises. But he is taking big risks, especially internationally, and a reckoning may yet come.
Washington has yet to learn whether the backlash among its allies over Trump's latest declaration will leave it alone in an hour of need. Anyway, Trump supporters who believe in his America First concept care little that the President is infuriating the country's friends around the world.
Trump has also been as good as his word in other areas.
As promised, he has moved to renegotiate NAFTA, pulled out of the proposed Trans-Pacific Partnership trade deal, walked out of the Paris climate accord, targeted the Iran nuclear deal and introduced a travel ban for residents of some majority Muslim nations, while adopting other radical immigration policies.
Trump vowed to preside over economic growth and set the stock market soaring. The gross domestic product expanded 3.3% in the third quarter, a three-year high, and the Dow just topped 24,000 points.
The message from the White House is that Trump is making good on his promise to shake things up.
"While previous presidents have made this a major campaign promise, they failed to deliver. Today, I am delivering," the President said.
Trump's re-election campaign jumped on the narrative of a President who is as good as his word.
"Once again, President Trump has demonstrated the kind of leadership that Washington does not recognize or understand ... with Donald Trump a promise made is a promise kept," said the campaign's executive director, Michael Glassner.
But with the presidency, things are rarely so cut and dried. There is a reason Trump was breaking ground on Jerusalem: Previous presidents judged that the political capital they could gain with a similar move was not justified by the risks. Those have included concerns of inciting Middle East violence or offending Palestinians by prejudging final status peace talks on Jerusalem, a city they also regard as their future capital.
The fate of Americans abroad -- easy targets in any violent backlash in the Middle East -- also weighs heavily on presidential consciences. Trump decided to take the risk anyway.
Critics might also point out that Trump's list of promises kept is an incomplete and politically expedient one.
He has tended to honor pledges that inflame his populist creed or pander to key constituencies like evangelicals and rich donors, including casino magnate Sheldon Adelson, both of whom had intense interest in Jerusalem.
But Trump has whiffed on some of his more complex pledges. He's hardly delivered health insurance "for everybody" like he said he would. The GOP tax plan, according to multiple independent studies, cuts access to health care and helps Trump's rich friends more than his working class supporters.
He also vowed to get tough with China on trade. But that has failed to materialize as he seeks Beijing's help in the North Korea nuclear crisis.
Trump's rash of promise keeping, including his decision to double down on derailing the Iran deal -- he refused to certify Iran's compliance in October -- his touting of a travel ban that appears to stigmatize Muslims and his defiance of the global consensus on climate change may reflect deeper political forces.
All that may explain why he was prepared to accept the risks of his Jerusalem move, which could stifle his administration's Israeli-Palestinian peace drive, unite US allies in Europe and the Middle East against him, and trigger extremism or reprisals against American citizens and interests.
In that light, his move seems less like a grand gesture of a rare promise-keeping politician than a cynical act of political calculation.
The polarizing nature of Trump's move was reflected in the responses of two veteran former US officials steeped in Middle East politics.
Elliott Abrams, who worked on George W. Bush's national security council, said the President's decision was a recognition of reality that Jerusalem is considered by Israel as its capital, and he scoffed at predictions that the President could incite an uprising as "completely overblown."
"There are intifadas among the Palestinians when the Palestinian Authority allows it and foments it," Abrams said on CNN.
But Aaron David Miller, a Middle East peace negotiator for Republican and Democratic presidents, said Trump was prioritizing his own political convenience over wider security interests.
"This had nothing, in my judgment, to do with the pursuit of Israeli-Palestinian peace," Miller said on CNN.
"This seems to be a political statement by a willful President determined, A, to deliver and to basically say to those who say, 'You can't do it, you wouldn't do it and you shouldn't do it,' to say, 'I can deliver.' "
It's not the first time that Trump has defied international opinion to make such a point — his moves on climate and Iran fit the same category.
But the cost of those moves could be less immediate than any backlash from the Jerusalem gamble.
The downside for deserting the fight against climate change, in rising sea levels and ravaged weather patterns, may be decades in the future; the loss of US influence to China yielded by exiting the TPP is intangible right now to American voters; if NAFTA falls apart the economic consequences may not be felt immediately.
But just because the President hasn't paid a price yet doesn't mean it will not happen.
And it's also possible, if his luck holds, that the President may become more trusting of his decisions, more disdainful of the advice of allies and establishment advisers and more tempted to give his instincts full rein.
Such behavior could have implications for the North Korean crisis as experts and allies warn of the consequences of a war on the peninsula that has long been considered as too horrific to contemplate.
Trump says the isolated state will not be allowed to threaten the United States with a ballistic missile tipped with a nuclear warhead -- a prospect that is just months away from becoming a reality.
And the President is getting a taste for living up to his promises.