After Doug Jones won Alabama’s U.S. Senate race in 2017 — the first time a Democrat had won a seat there in 25 years — it seemed as if Roy Moore’s political career was over. After all, he faced allegations that he initiated unwanted sexual contact with teenage girls when he was in his 30s. (Moore has denied the allegations, dismissing them as “fake news.”)

But now Moore has decided to run for the Senate again. On Thursday, the former chief justice of the Alabama Supreme Court announced his bid — and his new campaign can’t be entirely written off. Yes, Moore is defying the wishes of many Republicans, including President Trump, who said in a tweet last month that “Roy Moore cannot win.” But Moore still has a passionate base of support, particularly among conservative evangelical Christians. So the main question for his candidacy moving forward will be whether he can attract voters beyond his base.

As things stand, he could have enough backing to reach a primary runoff — Alabama requires a nominee to win a majority of the primary vote or the top-two candidates must face off in a subsequent election. However, while Moore would probably struggle to win the majority support necessary to advance to the general election, others in the field might have weaknesses Moore could exploit.

With Moore’s announcement, there are now four notable candidates running, with a fifth set to join the race. The two early surveys of the Republican primary field that we do have suggest that Moore could earn support from 18 to 27 percent of the primary electorate. It’s unclear, though, how much Moore can raise his ceiling of potential support. And that’s because many in his own party have a negative opinion of him. In April, 29 percent of Alabama Republican voters in a Mason-Dixon poll said they had an unfavorable opinion of Moore, with 34 percent having a favorable opinion and 33 percent neutral. And according to an internal poll recently released by primary rival Tommy Tuberville, a former Auburn University football coach, Moore’s net favorability among Republicans was worse than any of his rivals. Put simply, these numbers are a far cry from the 2017 primary, when Republicans liked Moore more than either of his two main opponents: then-Sen. Luther Strange, who had been appointed to the post, and Rep. Mo Brooks.

But there is one factor working in Moore’s favor — a crowded primary field. Because the eventual GOP nominee stands a good chance of beating Jones in the general election (Alabama is 27 points more Republican than the country as a whole), even more candidates could join the race. A large primary field may fragment the vote, making it unlikely that a candidate could win a majority and avoid a runoff and making it easier for Moore to advance to a runoff with only the support of his base.

So far, Rep. Bradley Byrne and the aforementioned Tuberville are the major contenders, but it appears that Alabama Secretary of State John Merrill is also gearing up to run after filing with the Federal Election Commission. (He has said will announce his decision next week.) Additionally, State Rep. Arnold Mooney received an endorsement from the Senate Conservatives Fund, a political action committee that backs conservative Republicans. There is also the chance that former Attorney General Jeff Sessions will decide to run for his old seat and clear the field, a possibility suggested earlier this week by Republican Sen. Richard Shelby, Alabama’s senior senator.

But if Moore does finish in the top two in the primary — without winning a majority — and makes it to a runoff, it still would be really hard for him to clinch the GOP nomination. That’s because he could no longer run as a factional candidate. But never say never — some of Moore’s major opponents have potential weaknesses. A political outsider, Tuberville might have an attractive profile in football-mad Alabama, but he voted in Florida just last November, opening him up to “carpetbagger” attacks. Byrne, probably the establishment favorite at this point, had a hard time in past primary battles for governor (he lost) and representative (he narrowly won), and he was critical of Trump in the 2016 cycle, although he did support the GOP ticket in the end.

The point is that Moore does have a path — especially a path to a primary runoff if there’s a crowded GOP field. And if he does get there, he would be only one step away from a rematch with Jones. National Republicans may have an “Anyone But Moore” attitude, and GOP groups would undoubtedly pound Moore with negative ads, but remember that a Trump endorsement of Strange couldn’t stop Moore in 2017. So it’s not impossible that Moore does end up winning his party’s nomination.

Trump said “the consequences will be devastating” to his agenda if that happens. And that might be true — Moore would probably improve Jones’s chances of winning reelection. (Jones even egged on Moore to run again.) But even as damaged as he is, Moore would still have a decent chance of winning a general election in conservative Alabama, and that is surely a big part of why he’s running again.

Roy Moore announces bid for US Senate