President Barack Obama on Wednesday will nominate Merrick Garland, a veteran federal appeals court judge viewed as a moderate, to the U.S. Supreme Court, Democratic Senator Charles Schumer told Reuters.

The nomination of Garland, 63, who currently serves as chief judge of the U.S. Court of Appeals for the District of Columbia, would set up a potentially ferocious political showdown with Senate Republicans.

Garland, 63, is a long-time appellate judge and former prosecutor who Obama also considered when he filled two previous Supreme Court vacancies. Federal appeals court judge Sri Srinivasan also had been a finalist for the nomination.

Obama said in a statement released by the White House that he will unveil his nominee at 11 a.m. EDT (1500 GMT) in the White House Rose Garden. Schumer is a member of the Senate Democratic leadership.

Obama has been searching for a replacement for long-serving conservative Justice Antonin Scalia, who died on Feb. 13.

Garland, who in the past has earned praise from lawmakers of both parties, was named to his current job by Democratic President Bill Clinton in 1997, winning Senate confirmation in a 76-23 vote. Prior to that, he served in the Justice Department during the Clinton administration.

“I’m confident you’ll share my conviction that this American is not only eminently qualified to be a Supreme Court Justice, but deserves a fair hearing, and an up-or-down vote,” Obama said in the statement ahead of his scheduled announcement in the White House Rose Garden.

Senate Republicans have vowed not to hold confirmation hearings or a vote on any nominee picked by the Democratic president for the lifetime position on the court. Senate confirmation is required for any nominee to join the bench.

Obama said he hoped the Senate would do its job and “move quickly to consider my nominee.”

Without Scalia, the nine-member Supreme Court is evenly split with four liberals and four conservative justices. Obama’s nominee could tilt the court to the left for the first time in decades.

Republicans, hoping a candidate from their party wins the Nov. 8 presidential election, want the next president, who takes office in January, to make the selection.

Billionaire Donald Trump is the leading Republican presidential candidate. Obama’s former secretary of state, Hillary Clinton, is the front-runner on the Democratic side.

Republicans and their allies already have geared up to fight Obama’s nominee. Republican National Committee on Monday announced the formation of a task force that will work with an outside conservative group to spearhead attack ads and other ways of pushing back against Obama’s choice.

The U.S. Court of Appeals for the District of Columbia Circuit has served as a springboard to the Supreme Court for several justices including Scalia in recent decades.

Obama may have been looking for a nominee who could convince the Republicans to change course. Garland could fit that bill with moderate record, background as a prosecutor and a history of drawing Republican support.

Garland was under consideration by Obama when he filled two prior high court vacancies. Obama already has named two justices to the Supreme Court: Sonia Sotomayor, who at 55 became the first Hispanic justice in 2009, and Elena Kagan, who was 50 when she became the fourth woman to ever serve on the court in 2010.

The Obama administration also regarded Garland as a future compromise choice if another vacancy opened in an election year with the Senate under Republican control, according to Obama advisers at the time and others weighing in on the current nomination. That is the situation now confronting Obama.

Presidents tend to pick nominees younger than Garland, so they can serve for decades and extend a president’s legacy. But Obama may reason that the choice of an older nominee might also entice Senate Republicans into considering Obama’s selection.

The Indian-born Srinivasan, 49, would have been the first Asian-American and first Hindu Supreme Court justice.

Trump, speaking on ABC’s “Good Morning America” program, said it was critical for Republicans to take back the White House to avoid Democrats shaping the Supreme Court.

“You have four Supreme Court judgeships coming up, and that would mean they would take over, that would mean for 50 years, probably, this country will never be the same,” Trump said.

“The Republicans should do exactly what they are doing. I think they should wait till the next president and let the next president pick,” Trump said.