One of the highest-stakes battles of Donald Trump’s presidency begins Monday: the U.S. Senate confirmation hearing of Supreme Court nominee Neil Gorsuch. Gorsuch was selected by Trump to succeed Justice Antonin Scalia, who died last year. And, like Scalia, Gorsuch is a conservative with a top-notch resume. That combination in a Supreme Court nominee has tended to lead to confirmation. Indeed, Republican senators seem united behind Gorsuch, while Democrats haven’t found a clean line of attack against him.

So Gorsuch seems likely to be confirmed by the Senate, but the big question is how? Will Democrats filibuster his nomination, requiring 60 votes to cut off debate, as some senators — including Minority Leader Chuck Schumer — have suggested? If so, can Republicans (with 52 seats in the Senate) find eight Democrats to vote for cloture (i.e., end the filibuster)? If not, will Majority Leader Mitch McConnell do away with the filibuster on Supreme Court nominations?

Much will depend on how the Gorsuch hearings unfold, but we can get a sense for the baseline by looking at past Supreme Court confirmation votes. If nothing crazy happens at the confirmation hearings, Gorsuch can probably expect around 55 votes for confirmation, according to a model I created of nomination hearings dating back to Robert Bork’s in 1987. The model looks at a nominee’s ideology, qualifications and public approval rating; each senator’s ideology and willingness to vote against his or her party; and the president’s approval rating. Basically, this is just a systematic way of looking at how all those factors have interacted in past confirmation votes. The model isn’t perfect by any means; Gorsuch could get 60 votes for confirmation or — if the hearings go poorly — perhaps even fewer than 52.

But even if the model is right and Gorsuch is starting with about 55 “yea” votes, that fact doesn’t get us very far. The model looks at up-or-down voters, rather than cloture votes, so if Democrats filibuster we’re still left wondering whether there are eight Democrats willing to buck their party and vote to end debate even if they then vote “no” for confirmation. The model can, however, give us an idea of which Democratic senators may be more favorably disposed to Gorsuch, and therefore more likely to vote for cloture.

The model, not surprisingly, suggests that more moderate senators and/or senators who have shown a willingness to buck their party are most likely to vote for Gorsuch and, presumably, cloture. These are senators such as West Virginia’s Joe Manchin, North Dakota’s Heidi Heitkamp, Missouri’s Claire McCaskill, Maine’s Angus King, Virginia’s Mark Warner, Delaware’s Tom Carper, Colorado’s Michael Bennet, Florida’s Bill Nelson and Montana’s Jon Tester. These nine have also issued statements insisting that they have an open mind about Gorsuch and are waiting for his confirmation hearings. Then there are senators who might vote for cloture for nonideological reasons but are still unlikely to vote to confirm Gorsuch. Sen. Chris Coons of Delaware, for example, said he doesn’t want to set a precedent of blocking a nominee for revenge — merely because the other party stonewalled your nominee, as Republicans did to Merrick Garland.

Another factor: Democrats take on some long-term risks if they filibuster Gorsuch. Trump wants Republicans to use the “nuclear option” — abolishing the filibuster on Supreme Court nominations — if Democrats refuse to allow an up-or-down vote. Were Trump to get another chance at nominating a justice, and if the filibuster were abolished, Trump could try to put someone far more controversial than Gorsuch on the court. Democrats may want to keep their powder dry for a nominee like that, or one that would shift the court’s ideological balance. A Gorsuch confirmation would restore the conservative lean that existed on the court prior to Scalia’s death, with Anthony Kennedy being the swing vote.

On the other hand, Democrats are still angry that the Republican Senate majority wouldn’t even hold nomination hearings for President Obama’s choice to fill the Scalia vacancy, Garland. So going back to the Scalia-era court makeup may feel more like swindle than a restoration.

Importantly, the public likes Gorsuch. And while the public doesn’t vote on Supreme Court nominees, my analysis of past votes suggests public approval is correlated with how many votes a nominee receives in the Senate once you control for other factors. Public pressure, for example, is part of what helped Clarence Thomas get confirmed. In pretty much every single survey taken so far, more Americans have supported Gorsuch’s confirmation than opposed it. Gorsuch doesn’t have quite the approval that many nominees over the past 30 years have had, but he’s not far off.

NOMINEE APPROVE DISAPPROVE NET APPROVAL Ruth Bader Ginsburg 67% 21% +46 David Souter 61 17 +44 Stephen Breyer 53 11 +42 Clarence Thomas 59 23 +36 John Roberts 51 21 +30 Sonia Sotomayor 52 32 +20 Neil Gorsuch 50 31 +19 Samuel Alito 41 27 +14 Elena Kagan 46 34 +12 Robert Bork 30 41 -11 Gorsuch is mildly popular For nominees besides Gorsuch, this is the final poll taken before the nominee was sworn in or their nomination was rejected. For Gorsuch, this poll is the most recent one taken as of March 17, 2017. No poll asked Americans their opinions about

Anthony Kennedy before he was sworn in. Source: Roper Archive

So as Gorsuch’s confirmation hearings progress, keep an eye on his public approval. Democrats are still trying to build up opposition to his nomination, and if they can find an attack that sticks and turn the public against confirmation, that could make a difference. They are attacking him mostly on economic issues (as opposed to social issues), and more specifically, they are trying to portray Gorsuch as against the little guy. That may not be a bad idea given that Trump rode a populist wave to win in many of the red states where Democrats need the votes to defeat Gorsuch. Similarly, keep an eye on what special interest groups are doing; research has shown that interest group opposition can be key to sinking a Supreme Court nominee.

Unfortunately for Democrats, attacks on Gorsuch have so far seemed to fall short. Of course, nothing is guaranteed for a Supreme Court nominee. More Americans approved than disapproved of Bork’s nomination to the Supreme Court in 1987 before his confirmation hearings began. By the end of it, the public and flipped, and more disapproved than approved. Gorsuch seems unlikely to end up in the same camp, but we won’t know until hearings actually occur.