Ted Cruz’s twin victories on Saturday night in Maine and Kansas—coupled with his strong second-place finishes in Louisiana and Kentucky—likely mean he will emerge as the long-discussed, as-yet-unglimpsed “non-Trump” Republican contender. He has now won six states (as opposed to Marco Rubio’s one), and he appears to have benefited both from other candidates dropping out of the race and from some fine debate performances. But Cruz’s excellent night is also good news for Donald Trump. Cruz will not only have more trouble solidifying an anti-Trump coalition than Rubio—or at least a better version of Rubio—would have. Cruz’s success may also mean that the GOP establishment, which despises the Texas senator, will not go all out to stop Trump.

Cruz’s wins on Saturday were somewhat unexpected. Neither Maine nor Kansas had been heavily polled, but his win in the former was a big surprise, and his margin of victory in Kansas (more than 2-to-1 over Trump) was eye opening. Trump’s victories in Louisiana and Kentucky, although impressive in a vacuum, were also closer than expected. Cruz erased most of the huge lead that Trump had racked up in early voting in Louisiana, which strongly suggests that Cruz’s support surged in the past several days. All of this is very promising for Cruz.

Meanwhile, Marco Rubio again disappointed, both in terms of votes and delegates, managing to finish fourth (out of four) in Maine. (He missed the delegate threshold there, as well as in Kansas and Kentucky.) He continues to lag in Florida polls, and it’s hard to believe that he will get the infusion of money he needs in the next 10 days, or that the party’s establishment will rally behind him. Rubio’s campaign, in short, is almost dead.

As for John Kasich, he may still pull out a win in Ohio, but even if he does, he is short of money and unlikely to go anywhere after March 15. (His impressive showing in the Kentucky counties bordering Ohio does suggest strength in his home state.) It’s no surprise that Cruz, in his remarks on Saturday, called for Kasich and Rubio supporters to unite behind him. But even that would have its own complications, laying bare Cruz’s tenuous path to victory: If Rubio loses Florida’s winner-take-all primary, Trump will likely win the state and amass even more delegates.

This is the problem for the anyone-but-Trump crowd: Even if Cruz’s odds of winning the nomination have gone up, Trump’s odds of victory remain as robust as ever. His toughest competitor would be someone who had broad support within the Republican electorate and enough establishment support to fight through the convention. For months, pundits have thought that competitor was Marco Rubio. Now, it’s looking more likely that this hypothetical opponent never existed.

If Ted Cruz is the only alternative to Trump, it’s hard to see the Republican establishment uniting behind him. Cruz is hated in Washington D.C., and by media elites like Rupert Murdoch; he is also the only candidate thought to be as unelectable as Trump. If the choice is between these two men, it’s possible that #NeverTrump becomes #WhoCaresWe’reScrewedNoMatterWhat.

Trump may not appear to have been the big winner on Saturday. He didn’t live up to his polling numbers, and Cruz emerged as a clear second choice. But it may just be that this particular night marked the beginning of the end for those trying to save the party from his candidacy. “I want Ted. One on one,” Trump said in his victory speech on Saturday night, before calling on Rubio to drop out. His wish may come true.

Read more Slate coverage of the GOP primary.