The takeaways from Monday night's Iowa caucuses are clear for Republicans: Ted Cruz was powered to victory by social conservatives and his superior ground game. Donald Trump's supporters — as was widely suspected — were less attached to the political process than their preferred political performer, and he subsequently underperformed his polls. Trump is far from finished, but Iowa was an ominous start for the frontrunner. And finally, the much anticipated Marco Rubio moment is here.

Having been stuck in the mid-teens nationally and in most states for months, the Florida senator surged into a very strong third-place finish in Iowa. The conservative and national media began openly cheering for him last night. Just as John McCain's fourth place finish at 13.1 percent in 2008 was declared an astonishing victory, so will Rubio's close third be declared the most important result, in no small part because the polling suggests he would be the GOP's strongest general election candidate against Hillary Clinton.

As for Cruz: The favorite candidate of Iowa's social conservatives, like Mike Huckabee in 2008 and Rick Santorum in 2012, tends to outperform the pre-caucus polls. Cruz did just that, beating out Trump. Cruz does have a path to the nomination. He has to consolidate his grip on the parts of the party that strongly identify with ideological conservatism, and win over some Trump supporters in South Carolina. He would also benefit if in New Hampshire we see a three-car pile up between Rubio, Jeb Bush, and John Kasich. Rubio's support has been slipping in the Granite State for weeks, due to a barrage of attack ads from rivals. With big-time momentum coming out of Iowa, Cruz could capitalize on this.

Trump, on the other hand, does not get a strong boost out of Iowa. He seriously underperformed the polls. But even if polls in New Hampshire overstate his voter support in the way polls overstated his Iowa support, he is still on track for a massive win. Trump always looked like a more plausible winner of New Hampshire, a state that strongly supported the populist Buchananite revolt in the 1990s. He runs far better in the northeast and in the South. He has massive leads of 15 to 21 points in the polls in New Hampshire, South Carolina, and Florida. He is still an absolute force.

Still, the most immediate result of the caucus will be Rubio-mania. I've been teasing Rubio boosters in the media for declaring every other moment to be a "Rubio moment" while he lagged behind in most polls for months. But he finally broke through that mid-teens cap in Iowa. He ran competitively with Trump.

Pressure to drop out will fall hard on candidates who are assumed to be blocking Rubio's path. That means Bush, Kasich, and Chris Christie. Rubio has been talking up his electability. The hypersensitive search for a "Rubio moment" existed for a reason; the political and media class believes Rubio is the Republicans' best shot at defeating Clinton. Her last name and her '90s-style, DNC-inspired political brand evoke America's past. Rubio looks like the America that is coming into being, built by the post-1965 wave of immigration. Rubio wants to make that pitch: "Yesterday is over."

The other reason that Rubio-mania will take off is less inspiring. Rallying around Rubio will just be too strong a temptation for the GOP's elite and the most established organs of the conservative movement. Rubio's candidacy is essentially based on the premise that nothing from the George W. Bush era has to change for the Republican Party.

Nominating Rubio is a statement that the party does not need a course correction. It doesn't need to stand even more firmly with social conservatives or fight with greater zeal and brinksmanship, as Cruz has argued. Nominating Rubio is a statement that the party does not need to find a less aggressive or less interventionist foreign policy, as Trump, Rand Paul, and (to a lesser degree) Cruz have argued. Nominating Rubio is a statement that the party does not need to offer any policy changes to attract working-class whites, as the candidacies of Trump, Mike Huckabee, and Rick Santorum have, to varying degrees, suggested. Instead, they just have to offer Rubio's story of gumption and rising from under his working-class parents' knees.

Rubio promises to put ground troops in Syria. He offers a very large tax cut to families earning six figures, paid for in expanding deficits. His record on immigration is really not very different than George W. Bush's: a series of unconvincing promises to gain control of America's border, combined with a credible threat to radically expand legal immigration, and create a path to citizenship for millions who entered the nation illegally.

Most of the things that distinguish Rubio from his party are unpopular with the public, namely his support for comprehensive immigration reform and his extremely hawkish foreign policy. But these are very popular with the GOP's elites, and not at all hard to swallow for most conservative elites. Rubio-mania is practically guaranteed. He's the candidate of the future, after all. The GOP is just telling us the future looks exactly like the last Bush administration.