CONSERVATIVE U.S. judge Brett Kavanaugh was confirmed to the Supreme Court Saturday by a razor-thin margin in the Senate, ending months of partisan rancor over his nomination and offering Donald Trump one of the biggest victories of his presidency.

Kavanaugh was sworn in shortly after the Senate voted 50-48 in his favor — a move that cemented the high court’s shift to the right under the Republican leader, who has chosen two of the nine sitting justices.

Protesters rallied in Washington and other U.S. cities against the ascent of the 53-year-old judge, who has faced multiple allegations of sexual misconduct and been criticized for his angry partisan rhetoric.

The prolonged nomination battle has roiled American politics, disrupting the status quo on Capitol Hill and firing up both Republicans and opposition Democrats a month before crucial midterm elections.

The two-vote margin of victory made it the closest Supreme Court confirmation vote since 1881 — and by far the most contentious since Clarence Thomas in 1991.

“This is a historic night,” Trump told supporters at a rally in Kansas after signing Kavanaugh’s commission aboard Air Force One.

“I stand before you today on the heels of a tremendous victory for our nation, our people and our beloved Constitution.”

Kavanaugh’s nomination as a replacement for retiring justice Anthony Kennedy was controversial from the start — but the initial focus was solely on the conservative views held by the married father of two.

But his ascent to the Supreme Court was thrown into doubt when university research psychologist Christine Blasey Ford testified that he had sexually assaulted her at a party when they were in high school.

Ahead of the Senate vote, protesters vented their rage on the steps of the U.S. Capitol.

As they chanted “Shame!” and “November is coming!” police took several dozen demonstrators down the steps and put them in plastic flex-cuffs.

Later, the protesters moved to the Supreme Court, at one point rushing the steps and banging on the building’s ornate bronze doors. “I am here because President Trump mocked sexual assault victims,” said North Carolina native Kara Harrington, 50.

In the Senate chamber, the vote was disrupted on several occasions by angry protests from the gallery.

Kavanaugh’s confirmation reflects a high-water mark of the Trump presidency, before the halfway point: Republican control of the White House, the Senate and the House of Representatives, along with a firm conservative majority on the judiciary’s top court.

But the saga — fueled by ugly accusations and counter-claims aired at nationally televised hearings, followed by an 11-hour FBI probe to address the assault allegations — has inflamed political passions.

The nomination laid bare the partisan gridlock on Capitol Hill and the political polarization of America, ahead of the midterm Congressional elections set for Nov. 6.(SD-Agencies)