President Trump is losing.

There are few sentences which run more directly against Trump’s long-cultivated brand, but it’s true. The president who promised his supporters that they would get tired of winning is on the brink of losing — not for the first time, but never in a more public way. The increasing franticness of his outreach, those last-minute media appearances and the wild swings in his decision-making, has been chalked up to the medication he’s taking to combat the coronavirus. But they might also be read as the last-minute efforts of a candidate who’s down in the polls and dropping.

The national polling average from FiveThirtyEight tells the story. Trump’s deficit against former vice president Joe Biden is widening. National polling doesn’t win elections, as Hillary Clinton can attest — but if the state polling averages are as wrong as they were in 2016, Biden still wins by more than 100 electoral votes as of writing.

Show average, including

Arrows at right show the actual vote margin in each year.

Your browser cannot display this graph.

But why? Why might Trump’s narrow popular-vote loss in 2016 become a more dramatic rejection of the incumbent president?

Detailed new polling from Pew Research Center shows how the electorate has shifted away from Trump over the past four years. Two years ago, the research firm compiled a picture of the 2016 electorate validated against actual voter rolls. Comparing the demographic data from that analysis to the results of a new national poll — in which Trump trails by 10 points — allows us to see both current support and how that support has changed.

On the graph below, groups (listed at left) are ordered from biggest shift toward Biden to biggest shift toward Trump.

(For some groups, the 2016 data isn’t a perfect fit. Pew’s data for that election, for example, breaks household income around $75,000 instead of $80,000, a subtle enough difference that we drew the comparison anyway.)

Let’s start at the bottom. Trump’s position has improved relative to 2016 with a number of non-White groups, including Black women, Hispanic men and two non-White religious groups. This has been a concerted focus of Trump’s, with constant appeals to both groups. He’s made headway, which could help in a close election, either by dampening turnout for Biden or reducing Biden’s margins with the groups. But those groups still favor Biden by wide margins.

The problem for Trump is that, while he’s gained slightly with non-White voters, he’s seen erosion with key groups of White voters. Yes, he’s improved 18 points on net with Hispanic Catholics. But he’s dropped 25 points with White Catholics, a group which made up almost three times as many voters in the 2016 election.

Trump’s base has long been White men without college educations. He still leads with that group, according to Pew, but his support has dropped 23 points. Why? Trump’s own support with that group is down from 73 percent among 2016 voters to 60 percent in the new Pew poll, while Biden outperforms Clinton by 10 points.

This gets at an obvious disadvantage that Trump faces this year: His opponent is viewed much more favorably than his opponent four years ago. In September 2016, Trump was still seen with some skepticism by Republicans who ended up voting for him anyway, so his net favorability (those who view him favorably minus those who don’t) was minus-24, according to polling from Quinnipiac University.

Clinton’s, though, was minus-17, and, on Election Day, Trump won voters who viewed both candidates unfavorably by 17 points.

Now, Trump’s net favorability has improved to minus-14. But Biden’s is a wash; he’s seen as favorably as he is unfavorably.

In other words, the favorability gap for Trump is now twice as large as it was four years ago. Quinnipiac polling has further shown that voters who view both Biden and Trump unfavorably prefer Biden by more than 20 points.

That’s probably a significant part of why Pew finds big margins among nonpartisan groups, like independents (who prefer Biden by 18 points) or those who voted for a third-party candidate in 2016 (where Biden leads by 23).

Among those who didn’t vote four years ago, Biden leads by 16 points.

Not all of Trump’s current position is a function of his opponent, of course. His consistently low approval ratings, particularly on his handling of the coronavirus pandemic, make it much easier for voters to turn away from him. That the alternative is seen as more palatable to many voters, especially White men (who were a third of the vote in 2016) is an advantage.

Pew’s poll doesn’t show a huge shift among women or older voters, two demographic groups that have been key to Biden’s advantage in other polls. In fact, Pew’s data shows little change with either group relative to 2016. Combining no change with women with erosion among men, though, yields a big Biden advantage.

This is one poll, albeit one which offers more detailed demographic breakdowns and a clean comparison to 2016. The story it tells is an uncomplicated one: Trump’s seen a broad erosion of support without improvement among large voting blocs. Among the 50-plus groups in Pew’s data for which we can compare 2016 and 2020, Biden does better than Clinton with 44 while Trump improves among 14.

Trump may still win the election. But that’s why he’s currently losing.