With three victories behind him and even more on the horizon, Donald Trump has a clear path to the Republican presidential nomination. Which leads to a natural question: Could he win the White House?

The case for yes is straightforward. We live in the age of narrow victories, where 51 percent of the popular vote is a solid win, and 53 percent is an outright mandate. Donald Trump is erratic, offensive to many, and broadly unpopular. But with the GOP nomination, he would have the instant support of tens of millions of Americans—enough to reach a high plurality in a national election. From there, a sudden recession—the collapse of the Chinese stock market, perhaps—or a terrorist attack could drive swing voters into Trump’s waiting arms. On the morning of Nov. 9, given the right conditions, we could be looking at President-elect Donald Trump.

Or, as my colleague Josh Voorhees writes in a piece on Trump’s chances, “Trump has been proving politicos, pundits, and political journalists wrong for the better part of a year now. I’m not willing to count him out come fall.”

For all the above reasons, I wouldn’t count him out either. But epistemological caution shouldn’t blind us to the facts on the ground. For as much as he could win, the safe bet is that Trump would probably lose the general election, and then some.

It’s true that Trump is an opportunist who could easily contort himself for a general electorate, emphasizing his moderate positions on health care and foreign policy, and toning down his aggressive nationalism. But this also assumes a static political climate. For all their criticism of Trump in debates and on the stump, none of the Republican candidates have made a real effort against Trump. “Multiple Republican campaign sources and operatives have confided that none of the remaining candidates for president have completed a major anti-Trump opposition research effort,” reports Sam Stein for the Huffington Post. All of this would change in a general election. There, he would face the full fire of a Democratic Party that has spent eight months accumulating information for an anti-Trump deluge.

With the full support of the Republican Party, Trump could survive that attack. And negative partisanship—the degree to which people vote against the other party more than they affirm their own—means he’ll enter a general election with substantial Republican backing (assuming he wins the nomination outright). At the same time, judged by favorability ratings, Trump is far from the most popular Republican, and is the least popular candidate in the presidential race, period. When you combine his base unpopularity with Democratic attacks on everything from his bigotry to his business record, it’s hard to believe he gets a substantial improvement in his favorability for the general election.

Given her own general unpopularity, you might say the same for Hillary Clinton. The difference is twofold. First, unlike Trump and Republicans, Clinton is popular with the large majority of Democrats. And second, if she’s the nominee, she’ll also benefit from a rallying effect, boosting her numbers further. Come September, after the conventions, partisan Democrats will remember that Clinton is also a partisan Democrat, and move accordingly. The same would be true for Bernie Sanders, although he, like Trump, would also face a deluge of unfamiliar attacks.

All of this gets to something important. Right now, Trump is driving up turnout in nominating contests without prompting a counter-reaction within the Republican Party. As BuzzFeed’s Adam Serwer argued, this has a lot to do with the GOP’s electorate. Put simply, the vast majority of Republican primary voters are white, and many of them hold views that aren’t far from Trump’s, even if they don’t like him. Revulsion aside, he’s not activating a real opposition among GOP backers.

But he is activating opposition among voters writ large. Hispanic voters are fiercely anti-Trump (he has a negative 64 percent favorability rating among that group, according to a recent Univision poll), and Trump’s presence may drive millions more Latino voters to the polls to cast a ballot for the Democratic nominee. Indeed, national polling on the question is sparse, but state polling suggests massive unpopularity for Trump among Democratic constituencies. A recent Rutgers University poll of New Jersey has Trump at a 74 percent unfavorable rating with minorities in that state, a 66 percent unfavorable rating with millennials, and a 65 percent unfavorable rating with women. A Quinnipiac poll of Ohio shows a similar result, with a 71 percent unfavorable rating among millennials, a 66 percent rating among women, and a 94 percent rating among black Americans. Other surveys show similar results, with deep antipathy for Trump among blacks.

If these issues are borne out in a general election, then Trump will have an even larger problem than negative attacks. He’ll have a negative electoral map. With abysmal ratings among blacks and Latinos, Trump is uniquely unsuited to this year’s demographics, which—all things equal—has a modest tilt toward Democrats. With Marco Rubio or John Kasich, Republicans might have a chance with minority voters. With Trump, that’s gone. To win, he would need to bring a massive influx of new white voters and create a further swing towards Republicans among existing white voters, all without alienating moderate whites or sparking counter-mobilization from nonwhites.

The fundamentals of the election are also important. It’s obscured by horse race reporting, but topline conditions for 2016 show a tight race, with odds slightly favoring the Democrats. What does that mean? First, that the economy is decent. We don’t have the strong growth we need to resolve the output gap, but we’ve also left the doldrums of 2011 and 2012. Wages are up (slightly), more Americans are working, and fewer people are leaving the workforce.

It’s no surprise, then, that the other variable for forecasting the presidential election—Barack Obama’s job approval—is also trending upward. Since January, Obama’s job approval rating has grown 2.5 points in the HuffPost Pollster average, to 47.8 percent. If you isolate Gallup, Obama has been pushing 50 percent for the past month. A decent economy and a well-liked president are the necessary conditions for an incumbent party that wants to win a third term. For Trump—and any Republican—it would be an uphill struggle.

Yes, anything is possible. Trump could ride a reactionary wave to the White House. But not everything is probable, and the obstacles to a Trump victory are yuge. Trump worsens the GOP’s problem with minorities and single women, with no guarantee of a larger electorate to compensate for the loss. And Trump is so alien to parts of the Republican establishment that there’s a chance he could drive down GOP turnout among its most reliable voters.

We shouldn’t underrate Donald Trump, but we shouldn’t overrate him either. All things considered, he’s a loser.