Once upon a time, the idea of Donald Trump’s securing the Republican nomination for the presidency existed only in the realm of fantasy. But as primaries in four states now reside in the history books, and The Donald has claimed three wins and 81 delegates, fantasy is merging with possibility, if not quite yet reality.

True, Trump has a long way to go to reach the 1,237 delegates needed to cinch the nomination, but with Ted Cruz and Marco Rubio a distant second and third (17 and 16 delegates, respectively), and the Trump train racing full-speed ahead, Republican “leadership” sentiment is shifting from “It will never happen” to “We’d better make sure it never happens.”

Short of Trump’s dropping out (sorry folks, not happening) or a sudden political catastrophe that stops his momentum — very unlikely since the more crazy things he says, the more his supporters like him — some are positing that a Rubio-Cruz unity ticket might be the way to derail the Trump train. Jonah Goldberg, for example, wrote, “One possibility [to stop Trump) would be for Rubio and Cruz to cut a deal. Republican disarray is largely attributable to the fact that no so-called ‘establishment candidate’ secured much support from the conservative grass roots, and no grass-roots candidate secured much support from the establishment. If the two factions — which make up the overwhelming majority of Republican voters — could be unified, it might be enough to stop Trump.”

Of course, the key word is “if.” And judging by the present state of affairs, it’s a pretty hefty “if.”

After all, the Cruz-Rubio feud has pitted the two against each other in an attempt to “out-conservative” the other, while Trump — anything but a conservative — climbs atop the mayhem en route to the plurality podium.

As Mark Alexander noted yesterday, “Shamefully, one of the key factors propelling Trump’s candidacy among the larger field of contenders is the absurdly self-defeating fratricidal attacks between Republicans, most notably Cruz and Rubio.” Cruz is trying to paint Rubio as an “establishment” candidate. Meanwhile, Rubio is touting his refusal to attack fellow Republicans; namely, Trump — while simultaneously attacking fellow Republicans; namely, Cruz. (Though there are signs Rubio is starting to go after Trump.)

Indeed, the race for second is awfully heated where the prize is more appropriately titled “first loser.”

Yet, if the two would bury the hatchet — or at least hide it — they could potentially catalyze a primary win for conservative principles. Again, Alexander pointed out, “[I]n national head-to-head matchups, where Trump faces only Ted Cruz or Marco Rubio, he loses to both. But as long as Trump has three or more opponents, he’ll continue to win state primaries all the way to the GOP convention.”

Is a Rubio-Cruz (or Cruz-Rubio) ticket remotely possible? As David Harsanyi writes, “How likely could it be after all the bad blood? Well, it wouldn’t be unique. There were hard feelings between Reagan and the man who coined the phrase ‘voodoo economics,’ George H.W. Bush. The promise of power heals all wounds.”

While we’re not placing bets that Marco and Ted will hug and sing kumbaya any time soon, they should start seriously considering it. If they don’t, odds are increasing that Republicans may produce a nominee with a track record only a liberal could love.

A final thought from Charles C.W. Cooke: “[Thursday] night, as they stand on either side of Trump, Marco Rubio and Ted Cruz must find their resolve and all-but-machine-gun the man to the floor. Without breaks for water or silence for applause, they must explain that Trump is an entitled mess whose business record is so questionable that he managed to bankrupt a casino; that he is an unashamed fraud who didn’t even wait to be elected president before folding on Planned Parenthood and Obamacare, exactly like the ‘feckless’ Congress he is running against; that he is feigning religiosity to appeal to people he believes are rubes; and, above all, that whatever he may be pretending now, he has spent a lifetime screwing the little guy. They must repeat verbatim his previous words on amnesty; they must outline in detail how his policies will make life worse for everyone; and they must point out that a Trump nomination designed to ‘mix things up’ will result, eventually, in more of the same.”