Here are the 11 justices Republican presidential candidate Donald Trump says he would consider for the Supreme Court if elected president. (Sarah Parnass,Jenny Starrs/The Washington Post)

One of President-elect Donald Trump’s most important decisions will be choosing a Supreme Court nominee to replace the late Justice Antonin Scalia. And while Trump has not clearly signaled who he will pick, here are four predictions about the next Supreme Court:

1. Trump will appoint a conservative. What kind of conservative isn’t yet clear. 

During the campaign, Trump promised that he would appoint conservative federal judges. Toward that end, he published a list of 21 names he would consider for the Supreme Court if he won the presidency. How do these prospective nominees stack up ideologically?

To answer that question, I draw on measures known as “common space” scores that political scientists have developed to array presidents, members of Congress and civilian federal judges on a liberal-conservative scale. The scores are based on votes that members of Congress take, positions presidents announce on legislation, and the votes that judges cast in cases.

This gives us a single measure that we can use to compare the ideological leanings of different political actors. Negative scores mean that someone has liberal policy preferences, while positive scores indicate conservative leanings.

Using these measures, we can generate an ideological score for 12 of the people on Trump’s list. (I don’t have the data necessary to include state judges here.) In the chart below, each of those individuals are arrayed on left-right continuum. Scalia is included as a point of reference.


Eight potential Trump appointees have more liberal scores than Scalia, while four are more conservative. Regardless of which side they fall on, eight are clustered pretty close to Scalia, indicating that they would likely be justices in his mold.

Trump’s candidates vary substantially, though. For instance, Judge Thomas Hardiman has a slightly more conservative score than Justice Anthony M. Kennedy. Judges Steven Colloton and Raymond Gruender have preferences that are similar to those of Chief Justice John G. Roberts Jr. Utah Sen. Mike Lee, based on his votes in Congress, is clearly the most conservative pick on Trump’s list.

The chart suggests that it is virtually certain that Trump will nominate a conservative, most likely one whose preferences are closely aligned with Scalia. Of course, if Trump deviates from his announced list of 21 — not an impossibility given his penchant for surprise — then that may be less certain.

2. The court will get back to hearing its normal caseload.

During the 2015 term, the court heard 69 cases, but only has 48 on the docket in 2016. After Scalia’s death and Senate Republicans’ decision not to hold confirmation hearings for President Obama’s nominee, Merrick Garland, the court was one justice short. As a result, it took fewer cases, likely because an evenly divided court made it more difficult for justices to predict how the decisions would turn out.

But with Trump’s election and a one- or two-seat Republican majority in the Senate, a new justice will be confirmed, bringing the court back to full strength. When that happens, the court’s docket will return over the next term or two to the average of where it had been in the previous five terms, around 69 cases.

3. The court is not going to undo affirmative action programs — at least not immediately.

Even when the court adds a new (likely conservative) justice, it is very unlikely reverse its ruling in Fisher v. University of Texas at Austin, which earlier this year upheld affirmative action programs in higher education. The court won’t revisit this issue because the same justices who made up the majority in deciding this case are still on the court. Trump will simply replace one conservative (Scalia) with another.

But what happens if one or more of these justices leaves the court? Three of them are over 75: Justice Stephen G. Breyer (78), Kennedy (80), and Justice Ruth Bader Ginsburg (83).

If that happened, and Trump appointed a conservative justice as a replacement, the new median justice on the court would probably become Roberts. This would give an already powerful justice who was in the minority on affirmative action even more influence over outcomes on the bench. Should that happen, major decisions in this and other policy areas may change.

4. The court could move to weaken labor unions and expand gun rights.

With a new conservative justice, the door will be open for the court to hear cases in two policy areas in which it has recently acted.

For one, the court could move to weaken the power of labor unions. The court had a chance to do so earlier this year in Friedrichs v. California Teachers Association. Scalia passed away before he could cast what would likely have been a vote to prohibit mandatory union dues for government employees around the United States, limiting unions’ power.

Instead, the court deadlocked 4-4 and allowed a lower-court ruling — which permitted mandatory union dues to be paid by workers in government agencies in non-right-to-work states — to stand. A new conservative majority might alter that ruling.

The court may also expand the rights of gun owners beyond its rulings in 2008 and 2010. One judge that Trump has put forward, Diane Sykes, has already issued a decision in favor of gun owners.

In September, the Washington appellate circuit heard a case about the District of Columbia’s concealed carry law. If this court takes this case and issues a conservative ruling, then the requirement that a person must provide a good cause to obtain a concealed carry permit could be declared unconstitutional. If that happens, then Washington, D.C., along with Maryland, New York, New Jersey and other states that have this requirement, would have to rewrite laws to make it easier to get a concealed carry permit.

Kenneth W. Moffett is associate professor in political science at Southern Illinois University Edwardsville.