A general view of the U.S. Supreme Court building in Washington, U.S., November 15, 2016. REUTERS/Carlos Barria

WASHINGTON (Reuters) - President-elect Donald Trump plans to unveil his choice to fill the lingering U.S. Supreme Court vacancy around the time of his Jan. 20 inauguration after the Republican-led Senate refused to consider President Barack Obama’s nominee, a senior Trump aide said on Wednesday.

The top U.S. court has been down one justice since the death of long-serving conservative Antonin Scalia on Feb. 13, leaving it ideologically split with four conservatives and four liberals. Obama nominated appeals court judge Merrick Garland for the post on March 16 but Senate Majority Leader Mitch McConnell blocked the customary confirmation process from proceeding.

During an interview with conservative radio host Hugh Hewitt, Trump’s incoming White House Chief of Staff Reince Priebus said the president-elect had not yet had any in-person interviews with potential Supreme Court nominees.

“I think that’s going to be something that we’re going to start after the new year,” Priebus said. “And certainly by the time we get to inauguration, either shortly before or shortly thereafter, we’ll reveal the name of who our nominee will be.”

Scalia’s replacement could tilt the ideological balance of the court for years to come, restoring the long-standing conservative majority just at a time when it appeared liberals would get an upper hand on the bench. This could be pivotal in wide range of issues including abortion, the death penalty, religious rights, presidential powers, transgender rights, federal regulations and others.

Priebus said the age of the nominee will be a factor in Trump’s deliberations, possibly preferring a relatively young jurist for the lifetime post. Priebus said that “I tend to believe younger is better” and “certainly longevity’s a factor” but competence will be the most important component.

Trump previously unveiled a list of 21 conservative jurists he would consider for the job and said this month he had whittled the list down to “probably three or four.”

The U.S. Constitution calls on the president to nominate members of the Supreme Court, with confirmation of the selection in the hands of the Senate. McConnell’s Senate, in a move with little precedent in U.S. history, simply refused to consider the nomination, saying the winner of the Nov. 8 presidential election between Trump and Democrat Hillary Clinton should make the pick.