What are Donald Trump’s chances of getting his Supreme Court nominee confirmed by the Senate? That depends on who he picks — Trump needs to find a nominee that balances ideology with qualifications. A pick too far to the right may leave Trump with too few Democratic votes, while one lacking in qualifications could turn off even Republicans.

Trump is reportedly looking to place a conservative on the bench. The leading candidates appear to be federal court judges Neil Gorsuch, who has a sterling resume, and Thomas Hardiman, who is more ideologically enigmatic but who has the backing of Maryanne Trump Barry, a senior federal appeals court judge and Trump’s sister. A third possibility is William Pryor Jr., another federal appeals court judge, who is seen as the most outspoken conservative. All three judges would probably face stiff Democratic opposition, especially after Republicans refused to hold confirmation hearings for Merrick Garland. Still, it would likely be Pryor who would have the most difficult time getting through the confirmation hearings.

The big question is whether any of these judges can receive at least eight Democratic votes. Democrats have basically promised to filibuster Trump’s pick no matter who it is, which means Republicans will need 60 votes to invoke cloture and force an up-or-down vote on the nominee. While it is expected that pretty much every one of the Senate’s 52 Republicans will vote for whomever Trump nominates, that leaves the GOP in need of eight votes to overcome the filibuster. If the Trump administration can’t find those eight votes, don’t be surprised if Republicans try to eliminate the filibuster the way that Democrats previously did for other federal court nominations.

Indeed, Supreme Court nominations have become a lot more contentious since Robert Bork’s nomination was blocked after a bitterly contested confirmation battle in 1987. The ideology of the nominee has become the key litmus test for senators. In years past, very conservative candidates who had an impeccable resume, such as Antonin Scalia, would fly through the confirmation process. (Scalia did not receive a single no vote when he was confirmed.) Today, in contrast, Scalia would face the possibility a filibuster. Qualifications still matter, which is why someone like Scalia would have a shot, but ideology has swamped all other concerns.

We can model how the Senate is likely to vote on various types of nominees by looking at past confirmation votes and what influenced them. Regular FiveThirtyEight readers might recall that I used a similar model two years ago to plot the chances that former President Barack Obama would get a nominee confirmed. The model is based on research led by Lee Epstein, a professor at Washington University in St. Louis, that tries to explain senators’ votes on Supreme Court nominations using six variables:

The model isn’t perfect. For one, it projects the final vote, not the vote on cloture. Further, senators are influenced by how much the public supports a nominee. Same with interest groups. Those two variables — not accounted for in our model — will affect Trump’s nominee’s chances.

NOMINEE PREDICTED VOTES ACTUAL VOTES ERROR Robert Bork 52 42 +10 Anthony Kennedy 93 97 -4 David Souter 93 90 +3 Clarence Thomas 44 52 -8 Ruth Bader Ginsburg 92 96 -4 Stephen Breyer 86 87 -1 John Roberts 70 78 -8 Samuel Alito 58 58 0 Sonia Sotomayor 73 68 +5 Elena Kagan 70 63 +7

That said, the model gives us a good baseline for what to expect from different types of nominees. For this exercise, we can use previous nominees as stand-ins.

Here are several different types of nominees and how many votes the model projects each would get:

Most qualified, most conservative (as represented by Scalia): 56 votes Very qualified and very conservative (as represented by John Roberts, Harry Blackmun and Warren Burger): 64 votes Somewhat qualified and very conservative (as represented by Clarence Thomas): 52 votes Qualified moderate (as represented by David Souter): 76 votes Most qualified moderate (as represented by Sandra Day O’Connor): 97 votes Very conservative and moderately qualified (as represented by Samuel Alito and Bork): 56 votes Very conservative and completely unqualified (as represented by G. Harrold Carswell): 36 votes Average Republican nominee in the past 50 years: 53 votes

It seems unlikely that Trump’s nominee is going to fall short of 50 votes. The only two Republican senators who have a greater than 10 percent likelihood of voting against a Trump nominee under most scenarios are moderates Susan Collins of Maine and Lisa Murkowski of Alaska. The only type of nominee who would not be forecasted to get at least 52 votes is someone who is very conservative and completely unqualified. Keep in mind, the prototype for this nominee (Carswell) was accused of being a white supremacist, and his own supporters acknowledged he might be “mediocre.” In other words, Trump would really have to go off the deep end to pick a nominee that Senate Republicans find unpalatable.

But even if Trump’s nominee can corral all the Senate Republicans to win a straight up-or-down vote, it will be more difficult for that nominee to get to the 60 votes needed for cloture. Look at the three most recent nominees put forth by Republicans (Alito, Roberts and Thomas). All of them would be forecasted to get somewhere in the neighborhood of 52 to 64 votes — that doesn’t leave much room for error. If there’s a real push by interest groups against the nominee, or if public opinion turns against Trump’s choice, it’s easy to see how all three could fall short of the 60-vote threshold.

The results do suggest that Trump can help his cause by picking a very qualified nominee. That’s the big reason for that jump from 52 to 64 votes between a Thomas type and a Roberts type. It’s also why someone like a Gorsuch could be appealing to Trump. By picking someone with impeccable credentials, he would force Democrats to admit that the reason they oppose his nominee is purely political. That could help Trump corral a few moderate Democrats not up for re-election to support cloture, at the least, and maybe the nominee as well.

Who are the Democrats who might vote for a very conservative, very qualified nominee?

CHANCE OF VOTING FOR VERY CONSERVATIVE NOMINEE WHO IS DEMOCRATIC SENATOR VERY QUALIFIED QUALIFIED Richard J. Durbin 10% 2% Richard Blumenthal 10 2 Catherine Cortez Masto 11 2 Robert Menendez 11 2 Charles E. Schumer 12 2 Benjamin L. Cardin 13 3 Kirsten E. Gillibrand 14 3 Christopher Murphy 16 3 Debbie Stabenow 16 3 Patty Murray 17 3 Ron Wyden 19 4 Christopher A. Coons 19 4 Martin Heinrich 21 4 Tammy Duckworth 22 5 Maria Cantwell 24 5 Robert P. Casey Jr. 25 6 Jeanne Shaheen 26 6 Gary C. Peters 27 6 Amy Klobuchar 32 8 Dianne Feinstein 34 8 Margaret Wood Hassan 41 11 Tim Kaine 44 12 Jon Tester 47 13 Bill Nelson 48 14 Michael F. Bennet 50 15 Thomas R. Carper 55 18 Mark R. Warner 57 19 Angus S. King Jr. 62 22 Claire McCaskill 75 35 Heidi Heitkamp 83 46 Joe Donnelly 85 50 Joe Manchin III 95 76

In this scenario, seven Democrats have a greater than 50 percent likelihood of voting for the nominee. Some of these are who you’d probably expect: moderate red-staters like Joe Manchin of West Virginia, Joe Donnelly of Indiana, Heidi Heitkamp of North Dakota and Claire McCaskill of Missouri. Some might be a little bit more surprising, such as Tom Carper of Delaware (who voted for John Roberts in 2005), Angus King of Maine and Mark Warner of Virginia, who all have fairly moderate voting records. Of course, there’s no guarantee that this is how the vote would go. Some of these seven persuadable Democrats might wind up voting against Trump’s nominee, and there’s a decent chance that one or more of the other senators listed in the table could vote for a Trump nominee if that person is well-qualified and not too extreme.

Top-notch qualifications, though, won’t be enough for most Democrats if the nominee is too conservative. A Scalia clone is projected to get only 54 votes. Trump would strengthen his hand significantly by nominating a moderate. A perfectly qualified moderate is forecasted to receive 97 “yes” votes. (I’m a bit skeptical of that: A model is only as good as its inputs, and political polarization is even higher now than it was a decade ago, so it’s possible that the model overweights qualifications and underweights the importance of party unity or ideology. We’ll have more on a possible adjustment for this once Trump names his nominee.) Even a moderate with less-than-perfect qualifications does a lot better than a very conservative nominee who is very qualified. That could make Hardiman, who is more difficult to pin down ideologically, more appealing to Trump. Republicans, however, may worry that Hardiman could end up like Souter and vote more like a liberal once he’s on the court.

Chances are, though, that no nominee Trump selects will be considered, at the time of his confirmation hearing, as moderate as Souter was thought to be at the time of his confirmation hearing. Trump looks like he’s going to be picking someone who is closer to the average Republican nominee over the last 50 years. That sets the Senate up for potentially the most contentious Supreme Court nomination hearing in 25 years, one in which the Republican nominee would probably be approved in an up-or-down vote but may not be able to get the 60 votes needed to invoke cloture and force a confirmation vote.





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