Over the course of his career in politics, Donald Trump has attacked and diminished the essential institutions of his country's democracy. These include fair elections, the justice system and the media.
As a candidate, he told his supporters that the 2016 election was "rigged" against him. "They even want to try and rig the election at the polling booths, where so many cities are corrupt and voter fraud is all too common," he said, without evidence, at a rally three weeks before the vote.
After he won office, he railed against the outcome, claiming that millions of illegal voters had cast their ballot against him and deprived him of the majority of the popular vote. The accusation was baseless, but he was still making it months after he was installed in the White House.
The man who is President has repeatedly attacked judges, accusing those that rule against him of bias based on their political beliefs or their cultural heritage.
He has more than once accused the FBI, and the Justice Department as a whole, of being corrupt and politically motivated in its investigations into Russian collusion with his election campaign.
Any news story or opinion piece critical of him is "fake." Any positive story is award-worthy investigative reporting, in his opinion. He sells himself to his supporters as the only source of truth in America, and paints the mainstream media as an organized conspiracy against him and his base.
He bows to none of the niceties associated with his office, up to and including the requirement of not using the presidency to enrich himself and his family businesses.
He is bigoted, and he courts bigots. He is divisive, dishonest and nepotistic. He is also thin-skinned and possessed of an over-weening desire to win at all costs, two traits that informed his business tactics and reality-television persona long before he ran for office.
These corrosive aspects of his character – his supporters see them as the charms of the last honest politician in the world; his harshest critics see a despot in the making – are going to be even more prominent in the next three years of his presidency.
That's because his legacy will be in jeopardy. After startling electoral victories in Alabama and Virginia, the Democratic Party is resurgent. It could realistically take control of the Senate and reduce the GOP's majority in the House of Representatives in the mid-term elections in 2018.
What was only recently inconceivable is now entirely possible, and you can bet your last dollar that Mr. Trump will use every weapon in his arsenal to prevent it from happening. It will be a foretaste of his own re-election campaign in 2020, when he will have even more on the line.
Mr. Trump's electoral problem is two-fold. His approval rating is remarkably low, especially for a president in his first year in office; and, as the recent surprise election of a Democratic senator in Alabama showed, those who oppose him are highly motivated to get out and vote against his interests.
He has to fear that Democratic voters who stayed home in 2016 and helped pave the way to his narrow victory won't make that same mistake again, now that they are better acquainted with him.
Mr. Trump will have a legitimate record of accomplishment to sell to his own voters and to some undecideds. These include income-tax breaks, a surging economy, promises kept to renegotiate trade deals and to roll back environmental regulations, and, possibly, successes in foreign affairs that eluded his predecessors.
But many of those same accomplishments are divisive, and they won't sway his most ardent opponents in the least. He will need to do more than simply present his government's record if he wants to help Republicans keep their seats after 2018, and to win re-election in 2020.
The question that has to be asked is, how far will he go?
His strategies of indulging bigotry and nationalism, of being highly divisive and of attacking the credibility and neutrality of the checks and balances on his power, combined with his barrage of vainglorious tweets, helped him dominate American politics in 2017.
But they also foreshadowed the tactics of a politician who will stop at nothing to win re-election. If a desperate President Trump, trailing in the polls, doubles down on his worst traits in 2018 and beyond, American democracy could well be unrecognizable in three years from now.