He had campaigned on listening to the forgotten masses; the people who felt left behind by the economic progress, and alienated by the march of globalisation.
And his speech was a resounding reiteration of that.
"Today we are transferring power from Washington DC and giving it back to you, the people," he said. "For too long a small group has reaped the benefits, while the people lost."
He has little time for political process
Trump launched an attack on the very politicians who were sitting around him, chastising them for being all talk and no action.
"We will no longer accept politicians who are all talk and no action, constantly complaining but never doing anything about it," he said. "The time for empty talk is over. Now arrives the hour of action."
His critics point out that, as someone who has never held elected office, he does not yet know what it is like to try and change policy, and make rapid, substantial change.
His words may come back to haunt him - watch closely.
He believes Obama has left America in a mess
The most pointed line in his speech was undoubtedly at the end of his list of the problems facing America: "This American carnage stops right here, and stops right now."
Trump spoke of drugs and gangs running rampant through the United States, of "rusting factories", a failure of education systems, a lack of jobs.
David Axelrod, Barack Obama's former policy adviser, remarked that he could imagine Mr Obama thinking: "If you see carnage now, imagine what it was like when I was in your shoes eight years ago" - pointing out that at that point 800,000 jobs a month were being lost, while Mr Obama is handing over with 75 straight months of job growth.
That does not matter for Trump, however. He sees America as a mess, and he believes he is the man to change that.
He plans to make good of his "America first" policy
There has never been any doubt that Trump's entire world view is seen through the prism of "America first".
But that point was hammered home on Friday in an inaugural speech that constantly harked back to the phrase.
He said that trade, taxation, immigration and foreign policy would all be viewed through the lens of "America first".
And if there was any doubt, he spelled it out - speaking slowly, emphasising his words: "We assembled here today are issuing a new decree: from this day forward a new vision will rule our land. From this day onward, it's going to be only America first."
He believes protectionism is the key
Trump's policy of imposing tariffs on US businesses who relocate and try to sell their products back to the US won him the White House.
His supporters love the idea of a punishment for American businesses who move abroad, shedding US jobs.
Critics have pointed out that the price for that will be higher costs for consumers.
But Trump's speech showed he had not been swayed.
"Protection will lead to great prosperity and strength," he said.
He thinks patriotism will heal America's divisions
If Americans had been expecting Trump to deliver an olive branch to his opponents, they would have been disappointed.
The speech was combative and uncompromising; the message was 'this is why I was elected, and this is what I will do.' He made no attempts to assuage the fears of minorities, who have been so concerned by his election and the surge in hate crimes it ushered in.
But Trump did offer his own solution for an America which he admitted was divided.
The answer, he said, was patriotism.
"We will rediscover our loyalty to each other," he said. "When you open your heart to patriotism, there is no room for prejudice."
He sees his inauguration as a moment of hope
And while for over half of all American voters the inauguration was a dark day, for Trump it was a moment of hope.
A very different man to Mr Obama, in almost every way imaginable, Trump was never going to deliver the soaring, inspirational oratory for which his predecessor was famed.
But he did attempt to give his own version. Trump said that America can be positive about a new era - "ready to unlock the mysteries of space," and ready to make advances in science and technology.
His vision of hope made no mention of advances in human rights or equality.
He has little time for policy minutiae
Trump's spokesman Sean Spicer said on Thursday that the president would be presenting a "philosophical document," rather than a detailed policy agenda. And that he did.
If his visions had been backed up by comprehensive policy documentation, that would be one thing. But Trump has been roundly criticised by his opponents for offering no clear plan for how to carry out his ideas.
His broad brush, populist speech did nothing to assuage those concerns.
In brief: What Trump has promised to do on his first day in office
• Ask Congress to immediately deliver a full repeal of Obamacare.
• Begin rescinding Obama's executive orders on immigration.
• Begin working on an impenetrable physical wall on the southern border. He has said it is "the single first thing I'll do".
• Learn the difference between Hezbollah and Hamas. Trump admitted to interviewer Hugh Hewitt that he didn't know the difference, but "will know far more than you know within 24 hours after I get the job."
• Get rid of gun-free zones in schools and military bases. "My first day, it gets signed, okay? My first day."