Soon after he takes office, President-elect Donald J. Trump will have to make a big decision: Who will he nominate to be the next justice on the U.S. Supreme Court? Before the election, Trump vowed to name a conservative to the bench. Now he is expected to deliver on his word, with an announcement that he has said will come during the first two weeks of his presidency. Some Democrats have called on Trump to re-nominate Judge Merrick Garland, President Obama’s choice for the high court, but their pleas likely will fall on deaf ears. The Court’s four-four deadlock probably will continue until at least April (and perhaps until June when its current term ends). Yet thereafter the Court’s conservative faction is poised to regain the majority it had from 1970 up until Justice Antonin Scalia’s passing early last year.

All this, of course, assumes that the Senate approves Trump’s nominee, which may not be a sure bet. This Congress, Senate Republicans have a slim 52-seat majority. They would need at least eight Democratic votes to defeat a filibuster of a nomination to the Supreme Court under existing Senate rules. Those votes may be hard to get. Democrats are still bitter that Republicans refused to consider Garland’s nomination. In all likelihood, most of them will be in no mood to let bygones be bygones to cement a conservative Court for years to come. However, some of them may feel strong pressure to support Trump’s nominee. Among them: The ten Democrats up for reelection in 2018 in states that Trump carried. Other Democrats (e.g., institutionalists in the caucus) may also support Trump’s nominee to try to save their right to filibuster future Supreme Court nominations. Democrats could have more leverage in fights over subsequent vacancies (particularly of those seats now held by liberals). Yet that will not be the case if Republicans axe the filibuster (which some Democrats fear could happen if they block Trump’s upcoming pick to the Court).