Now that Donald Trump is just a few delegates away from the Republican nomination, conversation among commentators has turned to his electability and his “pivot” to the general election. The same pundits who ignored the polls to say Trump would lose the nomination now urge us to take his odds seriously. He’ll take on a more “presidential tone.” He’ll attack Hillary Clinton on all sides. He’ll be formidable. He might even win.

Or at least, that’s the argument.

But before we get there, we have to answer a simple question. How will Donald Trump improve on Mitt Romney’s campaign for president? What will he win that Romney lost?

Romney wasn’t a bad candidate. He ran a competent and largely professional campaign against an incumbent who presided over high unemployment and slow growth. No, Romney wasn’t favored, but he also had a better shot than most candidates who run against a sitting president. If you believe that Trump can win—absent an exogenous shock like a terrorist attack or recession—you need to show how he beats Romney. You need to move this from the realm of speculation and into the world as it exists.

The idea of Trump as a plausible winner is rooted in the same error that drove pundits to discount and dismiss him as late as the Iowa and New Hampshire primaries. Then, observers saw the polls—which accurately showed his appeal to a cross-section of Republican voters—but refused to believe them. It was unthinkable that a field of ostensibly talented candidates would fail to stop Trump before he gained traction.

That’s what happened. If Trump had entered the race as an Icarus-type—a candidate who shoots to the top but withers under the heat—then by the fall, he was something different. He was a genuine presence in a crowded field with real support among Republican voters. No one bothered to stop him. Afraid of alienating Trump’s supporters, GOP leaders disarmed themselves; fearful of Trump’s attacks, Republican donors refused to fund a confrontation; complacent about his threat, Republican candidates focused on clearing their respective “lanes” rather than stopping the leader in the field. By the time Republican voters went to the ballot box, Trump had cultivated a following.

None of that is operative in the general election. Unlike Republicans, Democrats plan to hit Trump with a fusillade of attacks from all directions. And they plan to exploit weaknesses that Republicans didn’t touch until it was too late to stop Trump. They’ll hit Trump for his open and vicious misogyny; they’ll publicize his history of racism and discrimination; they’ll attack him where he’s strong with stories of ordinary people he’s scammed and defrauded; they’ll emphasize the fact that he doesn’t know anything about the world or governing.

Fed on years of anti-establishment rage and white identity politics, Republican base voters cheered when Trump toppled traditional politicians and rallied to his side when he called for a wall with Mexico and a ban on Muslims. Like Sharron Angle, Todd Akin, and Christine O’Donnell, Trump is tailor-made for a distrustful and angry plurality of the Republican Party. But the same polls that showed Trump at the top of the GOP primary also put him far behind in a general election. Like his predecessors on the fringe, Trump is anathema to ordinary voters.

Which brings us back to our question. If Trump is a viable general election candidate—if he has a shot at the White House—how does he do it? How does he improve on Mitt Romney?

Let’s look at the popular vote. Trump needs to win about 3 million more votes to turn the tide. He needs to do that in an environment where the incumbent president is popular, the economy is growing, and most people are satisfied with their direction in life. By itself, that’s difficult.

Let’s look at an electoral map. To succeed where Romney failed, Trump needs to flip at least 69 electoral votes. If he wins the four largest swing states—Florida, North Carolina, Ohio, and Virginia—plus New Hampshire, he wins. If he breaks into the Midwest, he wins. If he captures the entire South, plus New Hampshire or Iowa, he wins.

But how does this happen in practice? Florida, for example, is critical. Republicans can’t win without it. To flip the state, Trump has to outperform Romney with Latino voters—there just aren’t enough non-Hispanic whites to make up the difference. How does Trump fare among Latinos?

Eighty-seven percent of all Latino voters have a negative view of Trump, according to a new Latino Decisions national survey. In Florida, it’s 84 percent. In other Latino heavy swing states like Colorado and Nevada, it’s 91 percent and 87 percent, respectively. If Trump loses 87 percent of Latino voters nationwide (and nothing else changes from 2012), the Democrats add North Carolina to their 2012 haul as well as 8 million more popular votes.

OK, well, what about black Americans? There aren’t any detailed polls of blacks vis-à-vis Trump, but most national surveys show disapproval in the 80 to 90 percent range. If black turnout stays at its present trajectory, Trump will need to crack 15 percent with blacks to peel critical swing states from Democrats. (A Trump who could accomplish that is also a Trump who is clearly winning.) No Republican has secured more than 15 percent of the black vote in 60 years.

Trump is deeply unpopular with women, too. Seventy percent hold a negative view, according to a recent Gallup survey. If Trump loses 70 percent of women, then he’s lost, period.

What about white voters? The white share of the electorate has shrunk 2 points to 69 percent, while the Hispanic, black, and Asian shares have grown. In fact, of the 10.7 million increase in eligible voters, the large majority comes from nonwhite groups. If nothing else about the 2012 results change, the Democratic candidate will win with more votes across the board. Given that fact, as Greg Sargent details for the Washington Post, Trump would have to outperform Romney by substantial margins among whites to win Rust Belt states like Michigan, Wisconsin, Ohio, and Pennsylvania.

Donald Trump begins the general election with a huge deficit in head-to-head polls, deep unpopularity, and major demographic headwinds. Unless he wins unprecedented shares of black and Latino voters, or, barring any improvement with nonwhite voters, unless he wins unprecedented shares of white voters, he loses. And he has to do this while running as the most unpopular nominee in 30 years of polling. He has to do it while running against a Democratic Party operating at full strength, with popular surrogates (including a former president) crisscrossing the country against his campaign. He has to do it with a divided Republican Party. He has to do it while somehow tempering his deep-seated misogyny and racism. All this, again, in a growing economy with a well-liked president—solid conditions for a Democratic candidate.

Donald Trump has to become a radically different person to win.

Donald Trump isn’t going to win.

Read more Slate coverage of the Republican primary.