Ted Cruz, the Texas senator and Republican presidential candidate, has been studying Syrian dictator Bashar al-Assad. Cruz admits that Assad, who has used chemical weapons on his own people, is a bad man. But Assad has come up with a clever strategy. With the aid of Russia’s air force, Assad is wiping out the more moderate elements of the Syrian opposition. Assad’s goal is to leave the world with only two choices: Leave him in power, or allow the only remaining alternative, ISIS, to take over Syria.

Given the choice, Cruz prefers Assad. In an interview last month, Cruz concluded: “If President Obama, aided by a lot of Washington establishment Republicans, succeeds in toppling Assad, the result will be that Syria will be taken over by ISIS and the radical Islamic terrorists. That’s worse.”

But Cruz hasn’t just bought Assad’s logic. He’s copying it. In the Republican primaries, Cruz’s goal is to eliminate every palatable alternative candidate, leaving the GOP with only two choices: himself or Donald Trump.

Cruz has adopted this strategy for two reasons. First, his colleagues despise him. No senator has endorsed him. In an interview published Wednesday, Bob Dole, the former Republican Senate majority leader, spoke for many leaders in the party: “Nobody likes him.”

Second, Cruz knows that Republican strategists are afraid of how he, as the presidential nominee, would affect the party politically. Two weeks ago, Karl Rove warned that Cruz, unlike almost any other candidate, would make the 2016 election “dicey” for Republicans if he were nominated. Other Republican pundits and operatives agree.

Polls justify these concerns. In six weeks of Gallup data, from December to mid-January, Cruz scored worse than most of his Republican rivals in net favorability among self-identified independents and Democrats. Among independents, Sen. Marco Rubio’s net rating was positive. Cruz’s was negative. Among Democrats, Cruz’s net rating was nine points worse than Rubio’s. When Gallup narrowed its analysis to respondents who were familiar with the candidates, the gap between Rubio and Cruz increased.

But the data also showed something else: As bad as Cruz’s numbers were, Donald Trump’s were worse. Trump’s net negative rating was 27 percentage points among independents and 70 points among Democrats. In head-to-head matchups against Hillary Clinton, Rubio scored almost two percentage points better than Cruz. But Cruz scored almost almost four points better than Trump.

Many Republican leaders are terrified of Trump. Rove predicted that if Trump were to win the nomination, “the GOP will lose the White House and the Senate, and its majority in the House will fall dramatically.” There’s evidence to support this concern. A poll taken for the National Republican Congressional Committee reportedly found that if the GOP were to nominate Trump, a 48 percent plurality of respondents would be less likely to vote for a Republican congressional candidate. In Arizona, a survey found that with Trump atop the ballot, 30 percent of “high efficacy” Republicans would be less motivated to vote, and 20 percent would be less inclined to vote for down-ballot Republican candidates.

That’s why Cruz has adopted the Assad strategy. For months, while Assad avoided conflict with ISIS, Cruz avoided conflict with Trump. Instead, Cruz targeted Rubio for sponsoring an “amnesty” bill. (Cruz also lied about his own role in the immigration debate.) Meanwhile, Rubio, Gov. John Kasich, Gov. Chris Christie, and Jeb Bush savaged one another. Not until Jan. 14, when the candidates met for their sixth debate, did Cruz turn his guns on Trump. In an interview with moderator Neil Cavuto after the debate, Cruz asserted:

More and more, this is coming down to a two-man race. The polling, the support, it is more and more looking like it is Donald Trump and me. … More and more people are coming behind us, saying, “Listen, you guys are the only campaign that can beat Donald Trump.” And so if it’s a two-man choice, people are making a choice.

In at least seven interviews since the debate, Cruz has repeated that it’s a “two-man race between me and Donald Trump.” Several times in the past three days, Cruz has used this argument specifically to write off Rubio. “A lot of the establishment had been behind Marco Rubio,” Cruz told Sean Hannity on Wednesday. “They’ve decided now he doesn’t have a path to victory, [so] they’re moving to Donald Trump.”

As a strategy to narrow the race, Cruz’s message is working. Senior Republicans are losing faith in Rubio and concluding that the nominee will be Trump or Cruz. But presenting yourself as the lesser of two evils isn’t enough to win. That’s why Assad is still in big trouble against ISIS—and why Cruz is still in big trouble against Trump.

Cruz has failed to learn Assad’s lesson: When a fight narrows to two repellent adversaries, each adversary feeds off the other’s unpopularity. ISIS’s atrocities drive many Syrians into the arms of Assad. But Assad’s atrocities drive other Syrians into the arms of ISIS. What Cruz and other defenders of Assad don’t understand is that if you leave Assad in power and force Syrians to choose between him and ISIS, you’re not killing ISIS. You’re keeping ISIS alive.

The same is true of Cruz and Trump. Some Republican leaders who despise Trump are beginning to accept him precisely because they see the race narrowing to two men. They know Trump is abrasive and erratic. But they’re more afraid of Cruz, because Cruz’s abrasiveness is ideological. That’s what the National Republican Congressional Committee’s pollster told Republican politicians at a recent private gathering: Cruz, by branding the GOP as extreme, would hurt the party’s House candidates more than Trump would.

And Trump isn’t as crazy as ISIS. He knows how to play nice when it suits him. In a two-man race against Cruz, Trump doesn’t have to be sweet, electable, or faithful to the Republican platform. He just has to be less of a disaster than Cruz. Already, Trump is making that pitch to the GOP elite. The Assad strategy might work after all. But Cruz won’t be its beneficiary. He’ll be its victim.

Read more of Slate’s coverage of the GOP primary.