Are we entering the final weeks of the Trump phenomenon, or do we stand on the brink of a full year dominated by The Donald?

Entering 2016, the political class is of two opinions about the presidential race. One side believes Donald Trump is an overwhelming force in the Republican field, and will either capture the party’s nomination or be dislodged only after a long and brutal fight. The other expects Trump’s campaign to collapse once voting begins, with Republicans sorting out the rest of the field to select a strong nominee for the general election.

We will begin to learn soon which is right.

We’ll also see shortly whether Hillary Clinton pulls away and cruises to the Democratic nomination, as the political insiders expect, or if Vermont Sen. Bernie Sanders can give her a real race for the prize.

There has been a lot of yapping and squawking about these questions over the past year, but the presidential race really begins in earnest now. Sure, what happened in 2015 mattered—but it’s all been jockeying for position in these final three weeks before the Iowa caucuses and New Hampshire primary, when the bulk of voters begin to pay attention and choose their candidates.

And, after all this long, overwrought lead-up, things will begin happening very quickly now.

Iowa decides on February 1; New Hampshire, as always, eight days later. Then, South Carolina and Nevada, the new, so-called “SEC Tuesday,” and an Ides of March cluster of big states, including Florida, Illinois, and North Carolina.

Just six weeks after the Iowa caucuses, Democrats will have chosen half their elected delegates, and Republicans a full 60 percent.

That rapid pace could benefit Trump in his quest to bully his way to the Republican nomination. His celebrity, and the media’s endless fascination with him—and his brilliant manipulation of them—has arguably prevented Republican voters from learning enough about the other candidates to choose one. The quick primary schedule—originally intended, ironically, to help an establishment frontrunner wrap up the nomination quickly and easily—could make it hard for any other candidate to consolidate the non-Trump share of the Republican vote.

However, history suggests that things can change rapidly once Iowa and New Hampshire make their choices.

A look at the rolling averages at Real Clear Politics in those two first-voting, high-information states shows that Trump’s support has been stagnant in both Iowa and New Hampshire for four months—holding steady between 25 and 30 percent in both states.

That lasting power demonstrates an impressive hold on his supporters, but also a stubborn resistance among the other three-quarters or so of the caucus and primary voters.

Right now that anti-Trump vote is too dispersed to threaten his status as frontrunner. But that should change as Iowa and New Hampshire effectively knock out all but two or three of the main candidates.

Further frustrating the GOP party elites in the Washington corridors of power, the biggest chunk of those non-Trump votes are currently leaning toward Texas Sen. Ted Cruz. Cruz, a smart and calculating Harvard-trained attorney turned Tea Party evangelical, is hated by most Beltway Republicans, who view him as reckless, duplicitous, and personally unlikable.

He has, however, impressively consolidated much of what you might call the anti-establishment Republican establishment: religious and far-right leaders, such as James Dobson of Focus on the Family, and Bob Vander Plaats of Family Leader. Cruz appears to be in the catbird’s seat in Iowa, and if he wins there could start taking away Trump’s support in the South.

Meanwhile, I find that there is considerable and growing agreement among those D.C. insiders on what should happen going forward: consolidation around Florida Sen. Marco Rubio.

They have given up on Jeb Bush, who has been an atrocious campaigner—you can see at FiveThirtyEight that Bush has received just one congressional endorsement since Thanksgiving, while Rubio has gotten 10. New Jersey Gov. Chris Christie became unelectable, to their view, after the notorious George Washington Bridge scandal. Ohio Gov. John Kasich they see as too awkward and goofy on the stump to possibly carry the party’s nomination.

Nevertheless, Rubio’s performance as a candidate thus far—including surprisingly weak fundraising numbers—has kept most of the party’s establishment on the sidelines, waiting to see what happens.

Switching over to the Democratic contest, we find a reversed dynamic: The party establishment has leapt into the fray, giving its full support to Clinton.

That has not stopped a large share of Democrats from choosing Sanders. He is polling even with Clinton in Iowa and New Hampshire, and impressively across the country.

The political elites shrug it off. As Charlie Cook argues, Bernie Sanders figures to overperform in caucuses, which play to the party’s ideological left; and New England, where he has a home-field advantage. That gives him a great head start with Iowa and New Hampshire, and he could top Clinton in either or both.

However, the Southern Democratic primaries are dominated by black voters, and so far nothing indicates that Sanders is making inroads there. Elsewhere, centrist Democrats who delivered states such as Pennsylvania, Ohio, California, and Texas for Clinton in 2008 figure to do so again.

Or at least, that’s the theory. And theories had a poor track record in the 2015 portion of the presidential campaign.