Paul Ryan has the worst job in politics. As the most powerful Republican in the country, he has to represent the party’s principles, maintain and manage an unruly majority in Congress, and now work to convince Americans that the G.O.P. hasn’t turned into the Party of Donald Trump. It’s a job he didn’t want in the first place—he had to be cajoled into the Speakership after John Boehner abruptly stepped down last year—and it’s a job that Trump seemingly delights in making impossible. And if Trump has his way, Ryan might not even have a job at all next year.

After weeks spent subtly distancing himself from Trump and disavowing his increasingly offensive comments, Ryan appeared to go too far Sunday when he tweeted a not-so-subtle dig at the Republican presidential nominee over his treatment of Khizr and Ghazala Khan, the parents of a slain Muslim soldier who was posthumously awarded the Purple Heart for his sacrifice in Iraq. On Monday, Trump hit back by tweeting a “thanks” to one Paul Nehlen for backing him up in his feud with the grieving military family. Nehlen just so happens to be challenging Ryan in the August 9 Republican primary for his Wisconsin congressional seat, turning their ensuing Twitter exchange into a kind of proxy war with Ryan, or at least the threat of one. (Nehlen politely thanked Trump in response: “My pleasure, Sir. Just want to Make America Great Again.”) The subtext (or, rather, subtweet) was clear.

Not that Ryan realistically has to worry about a Nehlen insurgency. A recent poll from Marquette University found that about half of registered voters in his district viewed Ryan favorably, while only 33 percent viewed him unfavorably. Prior to that, another poll indicated that Ryan, who was elected to the House in 1999, was still wildly popular among registered Republicans in Wisconsin’s First District, beating Nehlen 78 percent to 14 percent. While Trump supporter Sarah Palin promised back in May that she would work to get Nehlen elected if Ryan didn’t endorse Trump, his political prospects were never in serious jeopardy. (Though the threat of getting “Cantored”—as Eric Cantor was when the former house majority leader lost his seat in a shocking upset to an upstart Tea Party primary challenger—remains a terrifying possibility for any high-profile Republican.)

“I like Paul, but these are horrible times for our country.”

The real damage may be to the two men’s already strained relationship. For Trump to threaten to tip the scales against Ryan’s re-election, is a clear signal that the rift between the Speaker and Republican nominee may never be healed. While Ryan has endorsed Trump, he continues to hold him at arm’s length, constantly offering quiet denunciations of the nominee’s latest transgression and subtly hinting that the billionaire doesn’t speak for true conservative principles. And Trump, a man who prizes ring-kissing above all, clearly does not approve of Ryan’s understated criticisms—nor has he forgotten Ryan’s past slights. On Tuesday, Trump told The Washington Post that he was “not quite there yet” in endorsing Ryan in his House primary next week, mimicking Ryan’s infamous “I’m not there yet” response when asked in May whether he would endorse Trump. “I like Paul, but these are horrible times for our country,” the billionaire said. Ryan’s office fired back later Tuesday with a statement saying they hadn’t asked for Trump’s endorsement and don’t need it.

The 46-year-old House Speaker may have hoped that his troubles would end when he told the press that he believed that a Trump presidency would allow the G.O.P. to pass their agenda through Congress and that, if necessary, they would be able to check and balance Trump’s whims. When that failed, and Trump told him to “please be quiet,” Ryan might have believed that his problems would cease after the Republican convention, where he and his fellow Principled Conservatives™ made grand speeches about limited government and individual liberties while barely mentioning Trump. But it’s becoming harder to see how Ryan can continue criticizing Trump’s statements while expressing his support. The rhetorical gymnastics required are becoming too convoluted, and Ryan risks injuring himself. Not just because Trump’s offenses appear to be getting worse—prompting Barack Obama on Tuesday to call on Republican leaders to withdraw their endorsements—but because the nominee himself appears on the edge of turning on him.