This afternoon, House Speaker Paul Ryan essentially declared Hillary Clinton the winner of the 2016 presidential election. On a conference call with Republican representatives, he announced that he would no longer publicly defend or campaign beside Donald Trump. After a leaked videotape showed Trump boasting of his ability to sexually assault women, Ryan had apparently concluded his party’s candidate was doomed. Henceforth, he said, he would focus his efforts on preserving his House majority to act as a counterweight against Clinton’s inevitable presidency. He encouraged the members of his caucus to decide for themselves whether to support their party’s nominee, or to follow the lead of a growing number of their fellow Republicans and un-endorse him.

This might have seemed a gift to the members of his caucus, but it presents them with a vexing problem. Many of these politicians have supported Trump throughout the course of his notoriously fractious campaign. They supported him when he called illegal immigrants “rapists,” when he blamed Megyn Kelly’s menstrual cycle for her tough line of questioning during the primary debates, and when he called for the US to no longer allow Muslim immigrants. They supported him when he implied that “Second Amendment people” could violently overthrow a Clinton administration, when he encouraged violence against protestors at his rallies, and when he retweeted praise from avowed white supremacists. They supported him when he praised Vladimir Putin, and when he urged the Russians to hack into his opponent’s email system. Every time Trump had upped the ante, they had pushed in their chips beside his. Had they already invested too much of their reputation to bail on Trump now? To put it in poker terms, were they pot committed?

Running the Numbers

In poker, a player is said to be pot committed when they have already invested so many chips that it makes mathematical sense for them to continue betting a likely losing hand. Let’s say my opponent and I have each bet $900, leaving me with $100 left in my stack. That means the ratio of money in the pot to the money left in my stack is 18:1—I only have to bet $100 to potentially win $1,800. If I think I have better than a 1-in-18—or 5.6-percent–chance of winning, I should call the next bet.

To determine how to respond to Trump’s latest round of provocations, then, politicians need to perform a few quick calculations. They need to determine how large the “pot” is—i.e., how much they stand to benefit if they stick with Trump. They need to figure out how many “chips” they have left—what would remain of their reputation should they “fold” at this point. And they need to figure out the odds of Trump winning.

Using this math, a politician should only dump Trump if they can salvage some of their reputation by ditching him, and if they think his odds of winning are very small. That would seem to be the calculation that representative Jason Chaffetz made this weekend when he announced he would not vote for Trump. Chaffetz had already firmly established himself as a foe of Hillary Clinton; just last month, as chair of the House oversight committee, he requested an investigation into the deletion of Clinton’s email. And he hails from Utah, a fiercely Republican but notably Trump-chilly state. That means he still has plenty of reputational chips left, which is why, when the likelihood of Trump’s election took a hit on Friday, it was rational for him to pull his support—to fold his hand.

Until this morning, Mike Pence—Trump's vice-presidential nominee—seemed to be weighing a similar decision. Many of the Republicans who announced they couldn't vote for Trump said they would write in Pence's name instead. Some consultants this weekend were reportedly urging him to drop off the ticket. He was coming off of a widely-praised debate performance against Tim Kaine last week. He would seem to have plenty of reputational chips remaining should he ditch Trump. But, at least as of this writing, he has pledged his continued support. Perhaps he figured that, having cast his lot so profoundly with Trump at a time when few would, he had already invested most of his stack. And certainly the upside for Pence is huge if Trump wins; as vice-president, he would presumably be the front-runner for the 2024 presidential nomination. That's a big prize, potentially enough to go all-in on a long shot.

Paul Ryan faces a similarly tricky decision. His constituents don’t only include voters but the members of his caucus and the political press who determine his broader reputation. He has already sacrificed many chips by refusing to condemn Trump. And he faces larger risks if he does completely turn his back on him now; the Trump-loving members of his caucus can make life very difficult if they deem him traitorous, which they seem wont to do. All this means he will be left with very few chips if he decides to completely fold. At the same time, his potential upside if Trump wins is huge; Ryan is counting on a Republican president to help pass the conservative agenda he holds so dear. Presumably that’s why, for all his hemming and hawing, he has still not formally rescinded his endorsement.

A Harsh Calculus

Perhaps nobody has misplayed this entire affair more egregiously than Ted Cruz. Cruz, you’ll recall, refused to endorse Trump at his own convention, urging his listeners to “vote their conscience.” Cruz dropped Trump early, before many of his worst statements (but after some truly terrible statements about Cruz's family). This meant that, if Trump not only lost the election but became a pariah, he would have been one of the only Republicans who could claim to have opposed him—a huge stack of reputational chips. But somewhere over the last couple of months, Cruz must have concluded that the costs of not supporting him had grown too high. Perhaps he thought Trump was likely to win, as some polls were beginning to suggest, which would have left Cruz on the wrong side of history. Or perhaps the cost of continuing to oppose Trump had grown too high—the GOP could have threatened severe consequences for uncooperative Republicans.

In any case, Cruz threw a ton of chips into the pot when he eventually endorsed Trump on September 23. His timing couldn’t have been worse; three days later, Trump’s disastrous first debate performance sent his campaign into a tailspin. Nevertheless, last week photos and video emerged of Cruz phone-banking for Trump, a pained expression on his face. He was all in. Two days later, * The Washington Post *the leaked video. According to a recent NBC/Wall Street Journal poll, he now trails Clinton by 14 points in a head-to-head matchup. Fivethirtyeight.com gives him a 16-percent chance of winning. Whoops.

Still, the election isn’t over, and Republican politicians will continue to make their calculations based on their read of the ever-changing odds. Trump has been threatening to attack any Republicans who abandon him, which raises the potential risk of folding. And recent polling suggests the overwhelming majority of Republican voters want their politicians to stand by the nominee. For politicians with short stacks of chips—electorates who won’t forgive them, or not enough of a reputation to withstand the controversy—it probably makes sense to keep calling the bet, no matter how slim the odds of a Trump victory. But those sitting on larger stacks should keep one thing in mind: The hand isn’t over yet. Trump might say something even harder to stomach. There could be more tapes. At that point, it will be even harder for the players to fold. If they aren’t pot committed yet, they may be very soon.