As a result of South Carolina’s Republican primary, on Saturday, the race for the Republican presidential nomination is a three-man race: it’s down to Donald Trump, Ted Cruz, and Marco Rubio. Technically, Jeb Bush was the only of their onetime rivals to officially end his campaign in the wake of the results. He did so graciously and with the integrity he’s shown over the course of this campaign. Though he could have persevered, he didn’t. That suggests that Bush recognized the tragedy of the commons looming for his party, if not his nation, if he, Rubio, and John Kasich all continued their quest to emerge as the establishment alternative to Trump or Cruz—and he acted in the way that best served the public interest, rather than his own.

The same can’t be said of Kasich. And Ben Carson has seemingly spent the past three weeks campaigning for vengeance against Cruz, who he has accused of dirty tricks in Iowa; it’s increasingly clear that Cruz’s staff were not exactly wrong in their inference that Carson has ended his campaign for the nomination, even if they came to that conclusion on the basis of a CNN report about his travel plans rather than all the other contextual clues available.

So, the final three. Here’s how it looks to me: Trump’s chances of winning the nomination are even stronger, post-South Carolina, thanks to his double-digit margin of victory and the fact that Rubio finished in second place, but just a whisker ahead of Cruz. Those results mean that both Rubio and Cruz will stay in the race, and it’s likely that each will continue his efforts to drive out the other.

That’s unfortunate, in my view. I’d much rather see both spend the next week taking on Trump. He is, after all, the actual frontrunner. In going after each other, Cruz and Rubio—and their respective supporters—are only bloodying up whichever 40-something Cuban-American conservative freshman senator will eventually proceed to the final showdown with Trump, and thereby increasing the odds that the latter will ultimately prevail.

Plus, it’s unlikely that either Cruz or Rubio can score a knockout blow against the other before Super Tuesday, on March 1. Rubio continues to poll at third place nationally, but Jeb Bush’s departure from the race should bring him some reinforcements from the nation’s Florida fans. Cruz’s third place showing in South Carolina, meanwhile, tells me that a solid month of sustained attacks from every direction has taken a toll, and that damage may well linger. But South Carolina was Cruz’s most serious setback to date, and the worst one he’s likely to receive before March 1—unless Rubio somehow wins the Nevada caucus on Tuesday, which he apparently feels no pressure to do. So Cruz now has a full week to regroup before Super Tuesday, which includes some favorable terrain. If he wins Texas, as I expect he will, the media will probably discount it on the basis of home-state advantage. And if he loses, I’d agree that the people have spoken. But Texas does have a lot of delegates. Even if Cruz’s only gold medal from Super Tuesday comes from us yokels, that might—along with his blue ribbon from Iowa—mean that he ends the day with two more first-place finishes than Rubio.

That such a scenario is plausible, incidentally, is what concerns me most about Rubio. The fact that he has yet to win a contest in the traditional sense—receiving more votes than any of the other candidates on the ballot—doesn’t necessarily spell doom for his candidacy. I’ve seen it noted, since Saturday, that no Republican candidate has won New Hampshire and South Carolina and gone on to lose the nomination, but it’s hard to consider such rules of thumb heavily predictive when you think of how small the sample set is. Only 43 Americans have ever served as president. Prior to 2008, 100 percent of them were white men. Prior to this month, when Bernie Sanders won among Democrats in New Hampshire, no Jewish American had even won a primary. It is nonetheless likely that Hillary Clinton will win the Democratic nomination, in contravention of the Farmer’s Almanac, which tells us that no woman has ever won a major party’s presidential nomination. And it’s true that thus far Rubio has been competing in a crowded field.

Still, if Rubio’s going to win the nomination, he’s going to have to win some primaries at some point. The fact that his campaign hasn’t even declared a goal of doing so in any specific state prior to Florida, which will hold its primary on March 15th, has crossed the line from confident to blasé. Equally ominous to me, given my stated view that Trump is unfit for high office, it remains the case that Rubio’s ability to beat Trump remains a hypothetical—one that I’m dubious about, and that he’s not even making a serious effort to prove. On Saturday evening, he tsked that Trump lacks a “fundamental understanding of foreign policy.” Some Rubio supporters might count that as fighting. I’d call it offering a quotidian observation that any sentient observer could have offered on the day Trump announced his campaign with a speech casting unauthorized immigration in the United States as the result of an unexamined and bizarrely passive-aggressive approach to international relations on the part of our neighboring country, Mexico: “They’re sending people that have lots of problems. … They’re bringing drugs. They’re bringing crime. They’re rapists.”

And Rubio does know how to attack people for real; we’ve seen him do so to Cruz. He’s occasionally done so under the cover of bemused innocence, as in November, when he colored himself puzzled over Cruz’s claim that they had different positions on the 2013 comprehensive immigration reform bill, which Rubio co-authored and Cruz voted against. More recently, though, Rubio has been blunt enough; he has called Cruz a liar, and accused him of showing a fundamental lack of integrity. Setting aside whether those attacks are fair, the same charges can clearly be leveled against the frontrunner. I’d like to see Rubio stand up to Trump, and I’d be reassured to see him survive the red-faced attacks Trump would inevitably level in response, as Cruz did in Iowa. It’s theoretically possible that Rubio can do both. But until he does either, it’s foolish to assume that he will.