Donald Trump and Hillary Clinton at a presidential debate in October 2016. (Jim Young/Reuters)

It has been almost exactly one year since President Trump shocked the world by defeating Hillary Clinton in the 2016 election. And he might well do it again today.

Confronted with the events of the past 12 months and even Trump's unprecedented unpopularity — 59 percent disapprove of his presidency — a new poll shows that 2016 voters look as though they'd still pick Trump, albeit about as narrowly as they did before.

The Washington Post-ABC News poll asked respondents how they'd vote in a redo of the 2016 election, and, if anything, Clinton seems to have lost more ground than Trump. Among those who voted, 46 percent say they picked Clinton last year and 43 percent picked Trump — a slightly more favorable sample than the 2016 election, in which Clinton won the popular vote by two percentage points. But in a head-to-head rematch, Clinton's support drops even more than Trump's does, and they wind up in a 40-40 tie. Given that Trump overperformed in key, blue-leaning swing states, that means he'd probably have won again.

Interestingly, Clinton actually seems to have lost that ground because of disillusioned Democrats. Even as the Trump presidency has unified the Democratic Party against him and his policies, just 72 percent of Democrats said they would vote for Clinton in a rematch — vs. the 84 percent who said they did vote for Clinton last year. Trump's share of the Republican Party, meanwhile, dropped just five points from 89 percent who said they did vote for him to 84 percent who said they would do it again.

(Almost all of the Democrats who would no longer vote for Clinton would opt for a third choice — 9 percent go to Gary Johnson, Jill Stein or someone else — while the others would not pick a candidate. Trump does not pick up any of this support)

Clinton also loses 10 points in terms of support from nonwhite voters. While 64 percent say they voted for her, just 54 percent said they would do so in a rematch.

The utility of this question is, of course, limited. Clinton seems to be done with running for office, and there will not be a redo of the 2016 election. The question is purely hypothetical.

It's also perhaps true that Clinton supporters are understandably less enthusiastic about voting for a candidate who lost the last election. But that lack of enthusiasm tends to show up in responses to the first question — about whom they actually did vote for — and not necessarily the redo question. People sometimes won't cop to having voted for a loser, but this poll shows that Clinton maintains a three-point edge among these voters. Instead, the drop-off here occurs when we get to whether they'd vote for her again. And many say they wouldn't.

That's notable because they now know exactly what the alternative has been. And even as Trump's disapproval rating has reached a new high of 59 percent, he has still got enough of a base to win reelection if there were a rematch today.

Of course, that's if he wound up facing the same historically unpopular Democratic nominee that he did in 2016. If anything, Clinton's numbers appear to have gotten even worse in the year since her election loss; a poll last week showed that she is viewed even more unfavorably than Trump is. Trump certainly can't count on facing another opponent who is so unpopular in 2020.

But for those who think that Trump has been an unmitigated disaster as president and that he has no chance of winning reelection, it should be a bit of a reality check that he can still win under the right circumstances.

The kind of circumstances he was in a year ago today, for example.