"Given the unusual circumstances and very unusual personality involved, it's hard to see this working out well," one laconic Republican lawmaker said recently of the Roy Moore situation. The Alabama Senate race is shaping up as a catastrophe for the GOP, regardless of how it works out. But just how big a catastrophe? Here are six scenarios:

1) Moore withdraws from the race. That's the dream of many in the GOP. Under that scenario, a Republican write-in candidate would then be able to keep the GOP seat in one of the nation's reddest states. But there's a problem: Even if Moore quit today, his name would remain on the Dec. 12 ballot. And if Moore stays on the ballot, even after having withdrawn, he will likely still get a lot of votes. "Candidates typically retain somewhere in the neighborhood of 20 percent to 25 percent of their pre-withdrawal polling average if they quit a race but their names still appear on the ballot," 538's Nate Silver wrote recently. That seems particularly likely to be true in Alabama, given the devotion of Moore's following. So would a GOP write-in be able to defeat Democrat Doug Jones in what would amount to a three-candidate race, with Republicans divided between Moore and the write-in? Unlikely.

2) The governor of Alabama changes election day. Alabama Gov. Kay Ivey has already changed the day of the Senate election once. Her scandal-ridden predecessor, Gov. Robert Bentley, originally scheduled the election to replace former Sen. Jeff Sessions for November 2018, as part of next year's regularly scheduled midterm elections. But Ivey, who ascended to office after Bentley resigned in disgrace, moved the election up to Dec. 12. Now, she could change it again -- say, to a few months from now, or back to 2018 as originally planned. That would give the Republican Party time to regroup. But Ivey has said she has no interest in a new change. And even if she did, it is hard to see how that would make Roy Moore go away.

3) Moore stays in the race with a GOP write-in challenger. Yes, there is time, but many Republicans are deeply pessimistic about the possibility of success. This is a special election, they note, not a general election. That means significantly lower turnout, and it means a high proportion of that turnout will come from the motivated supporters of Roy Moore. A divided Republican vote -- some for Moore and some for the GOP write-in -- seems guaranteed to ensure victory for Jones.

4) Moore wins, and the Senate GOP tries to expel him. "If he were to be sworn in, he would immediately be in a process before the Senate Ethics Committee," Majority Leader Mitch McConnell said recently. That process would involve hearings, witnesses, evidence -- a long and excruciating ordeal during which Moore could defend himself, and attack his accusers, at length. How long? The Ethics Committee's investigation of Sen. Bob Packwood began in December 1992 and ended with a recommendation to expel Packwood in September 1995. (Packwood resigned before the Senate could act.) Moore's case would likely be a long and ugly process. And a precedent-setting one: The Senate has never expelled a member for conduct that occurred before the member joined the Senate. If McConnell and his colleagues tried to expel Moore on the basis of accusations of conduct dating 30 to 40 years before the campaign, they would set a new and potentially dangerous example.

5) Moore wins, and the Senate GOP does not try to expel him. This is, so far, an unspoken scenario. What if Moore won, and Senate Republicans simply allowed him to serve? Moore would have essentially half a Senate term; if elected, he would serve the remainder of Sessions' term, meaning he would be in office until the 2020 election. Republicans could shun him, if they chose. They could stand by as protesters dogged Moore's every move. They could condemn the embarrassing things he did. They could do everything they could to assure Moore is not elected to a full term in 2020. But the GOP could, in essence, recognize that the voters of Alabama made a choice, and even if Republicans nationwide viewed it as a calamitously bad choice, Moore is still a senator until the end of his (shortened) term.

6) Doug Jones wins. This is a very real possibility, regardless of what the GOP does. What would it mean for the Senate's Republican leadership? Just ask how hard it has been for the GOP to pass legislation with a 52-seat majority. It would become far harder with a 51-seat majority. Plus, losing the Alabama seat would make it easier -- not easy, but easier -- for Democrats to win control of the Senate in 2018. That would have profound effects. For example, President Trump could probably forget about putting another justice on the Supreme Court, should a vacancy arise. Trump and Republicans could forget about passing legislation, even with the lowered requirements of the reconciliation process. And Democratic committee chairmen would be running all the investigations of the Trump administration they like.

Six scenarios. For the GOP, six bad scenarios.