Democratic Sen. Joe Manchin announced Friday that he plans to vote for Judge Ketanji Brown Jackson to serve on the Supreme Court, likely assuring the confirmation of President Joe Biden’s nominee.

Manchin was a key vote to watch because he has bucked his party on some of its top domestic priorities. But Manchin has backed all of Biden’s judicial nominees so far, and he said he would continue to do so in the case of Jackson, who would become the first Black woman to serve on the Supreme Court.

“I am confident Judge Jackson is supremely qualified and has the disposition necessary to serve as our nation’s next Supreme Court Justice,” Manchin said in a statement.

Manchin’s announcement indicates that Jackson will have the support of all 50 Senate Democrats. That would guarantee her confirmation, as Vice President Kamala Harris could break a tie.

Even as the path clears for Jackson to join the court, Democratic hopes of securing significant Republican support for her nomination appear to be fading.

On Thursday, just hours after the hearings came to a close, Senate Republican Leader Mitch McConnell announced he will vote against Jackson’s confirmation. He said in a Senate floor speech that he “cannot and will not” support her for a lifetime appointment.

McConnell slammed the liberal groups that have supported Jackson, and he criticized her for refusing to take a position on the size of the nine-member court, even though that decision is ultimately up to Congress. Some advocacy groups have pushed for enlarging the court after three justices nominated by former President Donald Trump cemented a 6-3 conservative majority.

McConnell also cited concerns about her sentencing of criminal defendants — a subject that dominated much of the four days of hearings and was part of a coordinated GOP effort to portray her as soft on crime.