The contest for the 2016 Republican presidential nomination isn't so wide-open any more.
A race that just a few months ago included 17 hopefuls jumbled together in a chaotic mass is beginning to take on a more distinct shape.
As the campaign rushes towards the first real battles of 2016, the contours, for now, include: A handful of candidates who could win the more conservative voters in Iowa; a different group who are strongly competing in New Hampshire; and Donald Trump, who is polling very well in both states and appears to have built a small but stable coalition of support across the nation.
Neurosurgeon Ben Carson and Texas Sen. Ted Cruz have emerged as the strongest fundraisers and are the top candidates among those explicitly targeting the votes of the Christian conservatives who dominate the Iowa caucuses, although ex-Pennsylvania Sen. Rick Santorum and ex-Arkansas Gov. Mike Huckabee are likely to stay in the race until the Feb. 1 caucuses and could also do very well with this bloc.
Louisiana Gov. Bobby Jindal, who was also competing in this group of Christian conservative candidates, dropped out last week, conceding he had little chance of upending these four.
Meanwhile, ex-Florida Gov. Jeb Bush, New Jersey Gov. Chris Christie, and Ohio Gov. John Kasich, all far behind in the polls, are increasingly centering their campaigns on New Hampshire. Each is hoping a strong showing on Feb. 9 in the Granite State, which has more secular and moderate voters, will lead to centrist Republicans to coalesce around him in other states.
The person who finishes third among that trio in New Hampshire will face strong pressure to end his campaign.
Three other more moderate candidates remain in the race, but have little chance of gaining traction. South Carolina Sen. Lindsey Graham and ex-New York Gov. George Pataki never had much support, while businesswoman Carly Fiorina, after a brief polling surge, has fallen way behind and has much less money to spend than candidates like Bush to make a comeback.
The two most intriguing candidates are Trump and Florida Sen. Marco Rubio. Trump, despite intense opposition from key Republican strategists and both current and former elected officials, has a strong base of support among GOP voters. Since August, Trump has had between 19 and 29 percent support in every poll in Iowa, placing him either in the lead or in second place in all those surveys. In New Hampshire, Trump has led by double digits in nearly every poll.
In national polls, Trump's numbers have been remarkably consistent: he has between 22 and 29 percent of the vote in six surveys conducted by Survey Monkey between July and last week.
His support among Republicans without college degrees in particular has been sustained despite criticisms from both his opponents and the press about Trump's controversial remarks and bombastic style.
So far, Rubio is the opposite of Trump: he has strong support among the party elite but not with rank and file voters. The Florida senator is increasingly seen by Republican strategists and donors as the candidate with the best chance to win both more moderate and conservative Republicans in the primary and be a strong general election candidate.
But he has trailed in polls in Iowa and New Hampshire for the entire campaign so far and must win over Republican voters who may be wary of embracing the baby-faced young senator.
None of these candidates is a clear front-runner, at least according to metrics that traditionally predict who will win a nomination.
Trump leads in polls, but no recent presidential nominee, Democrat or Republican, has had such non-existent support from former and current elected officials in his own party. Rubio is far behind in Iowa and New Hampshire, and the last person to recover from losses in both those states and win the primary was Bill Clinton in 1992.
Carson has no experience in elected office, Cruz is more conservative than GOP nominees have been in the past, and Bush's operation has spent millions of dollars with little to show for it in the polls.
Much about the GOP race will be unknown until people actually start voting in February. But over the next two months, two things could happen that would shift the race.
First, candidates who have little chance of winning and are struggling to raise money will traditionally start to withdraw, boosting the remaining candidates. This has already happened to some extent in the GOP race, with many of the donors and supporters of Wisconsin Gov. Scott Walker now backing either Cruz or Rubio.
Bush, Christie, Fiorina, Graham, Kasich, and Kentucky Sen. Rand Paul are all struggling individually, but they combined are getting about 30 percent of the vote in New Hampshire.
In particular, Bush, Christie, Kasich and Rubio are all running as mainstream Republicans who argue they could win the general election and have the government experience to be president. A field with one or two fewer candidates making that case could help those who remain.
The second key factor is whether key Republican officials take aggressive steps to steer the the GOP rank and file away from Trump, even before voting starts. Privately, top Republicans are wary of Trump, and not just because many of them find his rhetoric and policy positions on issues like immigration abhorrent.
Nominating Trump, in their view, is a huge risk: he could not only be defeated by Hillary Clinton himself but result in the GOP losing control of the U.S. Senate and potentially the House if he makes controversial remarks during the general election that tar the entire party.
Key people in the Republican Party with access to major donors and huge influence, such as House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell, have some strong incentives to prevent Trump from becoming the Republican nominee.
So far, important Republicans have largely made clear their opposition to Trump in subtle ways, such as Mitt Romney saying recently, "I will support the Republican nominee. I don't think that's going to be Donald Trump."
Those kinds of passive-aggressive digs at Trump may have capped his support at 30 percent, but that's still a significant bloc in a multi-candidate field. Republicans have three levers they could use to aggressively fight Trump: starting a major super-PAC designed to attack him; a coordinated campaign of figures like Romney, Ryan, and others appearing on FOX news and other conservative outlets and directly urging voters to oppose the mogul; and unifying behind another candidate.
Some donors, like billionaire investor Paul Singer, are trying to lead a unification of the party elite behind Rubio. That kind of organized effort could happen even before the voting starts and give Rubio the kind of financial and organizational advantages to beat Trump, even if the mogul is strong in early states. (The establishment mobilized behind Romney before voting in 2012, making it much easier for him to survive some of his primary defeats.)
Over the last month, Rubio has received more endorsements from sitting U.S. senators and key donors than other candidates. But at least so far, he has nowhere near the party establishment support of Hillary Clinton this year or Romney at this point in 2011.
An organized "Stop Trump" effort has so far suffered from a kind of collective action problem. It's in the interests of many Republicans for Trump to be weakened, but no single group or organization in the party has been willing to spend the millions to do it.
Trump meanwhile has been covered very extensively by the press during his campaign. His near constant presence on television is the equivalent of tens of millions of dollars in campaign ads.
So far, the conservative Club for Growth has spent $1 million running commercials against him, and Kasich's super-PAC announced on Thursday it plans to spend $2.5 million casting Trump as unfit to be president.
It's not clear that $3.5 million is enough to stop Trump.
In fact, while this seems unlikely, there is an alternative scenario that could emerge in December and January: key Republican Party officials begin to start endorsing Trump and embrace him as the party's probable nominee.