For months and months, movement conservatives and elected Republicans—along with a non-trivial contingent of political commentators and data journalists—promoted as conventional wisdom an idea that was really much more akin to wishful thinking. That idea, boiled down to its essence, was that the very weirdness of the Donald Trump phenomenon—his undisguised bigotry, his total lack of governing experience, the unanimous (if not always vocal) opposition of Republican elites to his candidacy—would sooner or later doom him.

When Trump not only didn’t collapse, but built a commanding nationwide polling lead—which he is now converting into a substantial delegate lead—the conventional wisdom took a turn. Once the candidate field dwindled down to a two-or-three person race, the new thinking went, Trump would hit a ceiling. Even if he never exactly collapsed, Marco Rubio and Ted Cruz could slug it out to the GOP convention and conspire to deny Trump the nomination. Alternatively, a single challenger might defeat Trump outright.

In this latter scenario, Trump is assumed to be vulnerable from both directions. In a head-to-head against Cruz, he would succumb to the consolidation of the religious and ideological right, along with a meaningful segment of the Republican mainstream. Alternatively (and preferably, as far as most Republicans are concerned), Rubio would emerge and defeat Trump in the blue and purple states of the Northeast, the Rust Belt, and the West.

For a moment after Rubio’s unexpected (but very narrow) second-place finish in the South Carolina primary Saturday night, you could mistake his shiny mien for a glimmer of hope that Trump’s reckoning was at hand. Or, if not at hand, clearly visible in the middle distance.

But after brief scrutiny, and for several reasons, this second-best fantasy falls apart. First, and most obviously, this is still at best a three-man race between Trump, Rubio, and Cruz. If it never dwindles into a two-man race, then the most Republicans can hope for is a contested convention this summer. After attempting but failing to destroy Cruz’s candidacy a month ago, establishment Republicans are now pressed up against the back edge of their own sword. The Texas senator is in the race, and has no incentive to drop out—especially not before Super Tuesday, when a number of Bible Belt states (and his own) will hold their nominating contests. Trump, it should be noted, just routed the field across almost every GOP demographic, including evangelicals, in South Carolina.