After historic rule change, Senate confirms Neil Gorsuch to Supreme Court

— -- After a historic rule change, the Senate voted mostly along party lines, 54-45, to confirm Neil Gorsuch to the Supreme Court as its 113th justice.

Gorsuch, 49, who served as a federal judge on the 10th Circuit Court of Appeals in Denver, was nominated to the bench by President Trump in January.

The nation’s highest court now has its full complement of nine justices for the first time since the death of Justice Antonin Scalia in February 2016.

Three Democratic senators -- Joe Manchin of West Virginia, Joe Donnelly of Indiana and Heidi Heitkamp of North Dakota -- joined their Republican colleagues to vote yes on Gorsuch's nomination. One Republican senator, Johnny Isakson of Georgia, did not vote.

Gorsuch's confirmation marks the end to a bitter, partisan battle that began within hours after the sudden death of Justice Antonin Scalia on Feb. 13, 2016.

President Obama quickly nominated federal Judge Merrick Garland on March 16, 2016, to fill the vacancy. But Republicans led by Senate Majority Leader Mitch McConnell refused to consider Garland in the Senate, arguing that the next president should choose the nominee.

After Trump won the election, he nominated Gorsuch. Republicans praised the Denver judge as highly qualified and a fine replacement for Scalia, a conservative icon.

But many Democrats argued that Gorsuch's record was too conservative and that he failed to answer key questions about his judicial record during his Senate hearing last month. Democrats were still upset over Republicans' refusal to bring Garland's nomination up for a vote.

The long-running saga hit its climax yesterday when McConnell invoked the so-called "nuclear option" to stop Senate Democrats’ filibuster of Gorsuch's nomination. The GOP leadership effectively changed Senate rules so that from now on supreme court nominees no longer have to win 60 votes but can be confirmed by a 51-vote simple majority.

McConnell celebrated the confirmation of Gorsuch today, calling it "a proud day."

On the Senate floor following the vote, the majority leader expressed thanks President Trump as "the man who made this moment possible by sending us this outstanding nominee."

"I want to congratulate Judge Gorsuch on this significant achievement. We look forward to observing his good work in the years to come," McConnell said. "The confirmation process was certainly a significant undertaking."

Once Gorsuch is sworn in, the Supreme Court will have a conservative majority.

ABC News' Ali Rogin contributed to this report.