Donald Trump has Republican party leaders like Paul Ryan dreading the remaining months of this presidential election. Photo illustration by Lisa Larson-Walker. Photos by Brian Snyder/Reuters, Mark Wilson/Getty Images.

For roughly seven days in May, Donald Trump was on the upswing. Ted Cruz had left the race for president and Republican leaders were coming around to Trump’s candidacy, dutifully endorsing the party’s presumptive nominee. Prominent Trump skeptics were holding their tongues, and the most visible Republican lawmaker in the country—House Speaker Paul Ryan—was in talks with Trump about the party’s agenda for the fall. The real estate mogul still had ground to cover in the polls, but in that moment, if you squinted, he looked like a candidate who could win.

Then came Gonzalo Curiel. A federal judge, Curiel had certified a class-action lawsuit against Trump’s now-defunct for-profit school, Trump University. In May, he granted a request—from the Washington Post—to release Trump University documents to the public. The subsequent coverage was deadly. In response, Trump went on the offense, with a racist attack on Curiel’s impartiality. The same Republican leaders who endorsed him weeks earlier now balked at his rhetoric. Some withdrew their endorsements. Any momentum Trump had was gone, wasted in a matter of days.

Earlier today, the Washington Post and ABC News released their latest national poll of the presidential race, conducted last week, from the peak of the Curiel affair to the immediate aftermath of the massacre in Orlando. The numbers for Hillary Clinton aren’t great. The numbers for Donald Trump are unprecedented and catastrophic. Seventy percent of registered voters have an unfavorable view of Trump (including 88 percent of nonwhites), divided between 14 percent who are “somewhat unfavorable” and a whopping 56 percent who are “strongly unfavorable.” For comparison’s sake, Clinton’s total unfavorable rating is 55 percent. New polls from Bloomberg and NBC News show Clinton with a 12-point and a 7-point lead, respectively.

A presidential nominee with this standing doesn’t just lose in the general election; he brings his party down with him, wiping out an entire generation of leaders in one fell swoop. If Trump remains this unpopular through the fall—and if third-party candidates like Gary Johnson and Jill Stein don’t make substantial traction—he could cost Republicans control of the Senate and perhaps even the House.

Politicians, and the parties they build, want to win. And they’ll do anything it takes to reach that goal. But there are limits to this, imposed by interest groups, activists, intellectual leaders, and voters. Trump is a direct threat to the GOP’s ability to hold onto national power. Worse, there’s no indication he has the capacity to change. If there’s anything consistent in Trump’s politics, it’s nativism and racial prejudice, from his tirades against Japan in the 1980s and public attacks on the “Central Park Five,” to his “birtherism” during President Obama’s first term and his present-day condemnation of immigrants, Muslims, and Hispanics.

Judging from his past behavior, Trump will only get worse. Already, he’s running with the conspiracy theory that President Obama is in league with ISIS and other terrorist groups. Trump’s popularity is low. It can get lower. By the time we reach the Republican National Convention, Trump might be a zombie candidate: lifeless but still shambling forward, consumed by his most animal impulses.

So what do Republicans do? What could they do? At this late stage, the only alternative left is the party’s nuclear option—ignoring its primary voters and dumping Trump from the ticket in a hail-Mary attempt to save its congressional majority. For some conservatives, this is the obvious choice. “[T]here is not a single ‘bound’ delegate to the Republican National Convention,” notes David French, a staff writer for the National Review who briefly flirted with a third-party candidacy against Trump. “Not one delegate is required to vote for Donald Trump, Ted Cruz, Marco Rubio, or any other individual who ‘won’ votes in the primary process. Each delegate will have to make his or her own choice.”

There’s a reason we say “presumptive nominee” in reference to the winner in a presidential nomination fight: The status isn’t official until delegates ratify it at the convention. Our political norms and intuitions (the person with the most votes wins) are such that in the era of modern presidential elections, the presumptive nominee has always been the official one, but that doesn’t have to be the case.

The rules of the Republican convention don’t exist in advance. They are crafted by the rules committee before the convention meets. If it wanted to, a majority of that committee could change the rules of the nomination process, unbinding delegates from their respective candidates and allowing the party to choose a different nominee. As procedure, it’s straightforward. As politics, it’s dangerous.

The only way this happens is if Republican leaders sign onto the effort. And if they do, they will have voted to throw the convention—and the GOP itself—into complete chaos, opening the door to a massive backlash from Republican primary voters, who cast ballots with the expectation that the party would respect their choice. It’s a huge gamble that could (and likely would) destroy the career of anyone who touched it. Which means it probably won’t happen.

If it’s not going to dump Trump, then the most the party can do is distance itself as much as possible. And it’s already happening. On Tuesday, top Republicans like Paul Ryan and Senate Foreign Relations Committee Chairman Bob Corker condemned Trump for his response to the Orlando shooting. “I do not think a Muslim ban is in our country’s interest,” said Ryan, who a week ago was lamenting the “textbook” racism of Trump’s comments about Curiel. “I do not think it is reflective of our principles, not just as a party but as a country.”

Between now and November, there’s a good chance we’ll see something almost unprecedented in modern American politics: a world where the elected officials and elites of a political party are either indifferent to the fate of their party’s nominee or outright antagonistic to him. Where Republican lawmakers disavow their endorsements, where Republican office seekers obscure their ties, where the whole firmament of Republican electoral politics—operatives, activists, fundraisers—take leave for the season to let Trump flail on his own.