Sen. Jeff Merkley (D-Ore.) began an all-night protest on the Senate floor late Tuesday, promising to speak “as long as I’m able” in protest of the nomination of Judge Neil Gorsuch to the U.S. Supreme Court.

He finally ended his speech more than 15 hours later, on Wednesday morning.

“By stealing a Supreme Court seat for the first time in American history, the Senate is undermining the Court and the rule of law, and turning the highest court in the land into a political committee,” Merkley wrote on his official Facebook page. “This assault on our democracy demands as robust a resistance as we can possibly mount.”

Sen. Jeff Merkley says he's planning on holding the Senate floor *all night* to protest Judge Gorsuch & a 'stolen' SCOTUS seat —via @MSNBC pic.twitter.com/gNPB6oGOAv — Kyle Griffin (@kylegriffin1) April 5, 2017

Merkley began speaking around 7 p.m. Tuesday, lambasting his Republican colleagues over their refusal to hold a vote on Judge Merrick Garland during the administration of President Barack Obama.

“The majority team in this chamber decided to steal a Supreme Court seat. ... The majority said, ‘We intend to pack the court of the United States of America,’” he said. “It was a warfare tactic of partisanship.”

As the protest neared its eighth hour early Wednesday morning, the senator pointed to Gorsuch’s past rulings that some have deemed anti-women and anti-worker, including his decision in the Hobby Lobby case that found businesses don’t have to provide contraceptive services to their employees.

Merkley expanded on the views he called “too extreme for the Supreme Court” in a blog published by The Huffington Post:

“In the infamous Hobby Lobby decision, Gorsuch embraced the disturbing philosophy that corporations are people. Then he extended that philosophy to say that corporations should be able to impose their owners’ religious views on their employees’ medical care — preventing women from accessing contraception through their insurance plans.”

Merkley also read from a Politico article published Tuesday that alleged Gorsuch copied the writing structure of other authors in one of the judge’s books and an academic article.

Democrats on Monday hit the magic number of votes need to filibuster the Gorsuch nomination after Sen. Chris Coons (D-Del.) announced he’d join the effort led by Senate Minority Leader Chuck Schumer (D-N.Y.). Schumer has said it’d be “virtually impossible” to come to an agreement with Senate Republicans over Gorsuch and has called on President Donald Trump to put forth a less politicized nominee.

Senate Majority Leader Mitch McConnell (R-Ky.) has refused any such plan, saying Gorsuch would be confirmed no matter what. He has continued to threaten the “nuclear option” when it comes to the judge’s confirmation vote ― a rule change that will allow the nomination, and any future ones for the Supreme Court, to go forward with a simple majority rather than needing a 60-vote threshold.

But despite some reservations among Republicans, McConnell said Tuesday that he has the votes to do just that.

According to Roll Call, Merkley’s speech, which clocked in at 15 hours and 28 minutes, was the eighth-longest Senate floor speech since 1900.

Merkley ended his lengthy floor speech at 15 hours, 28 minutes -- making it the 8th longest since 1900. https://t.co/DBc8Fwa8pG pic.twitter.com/uKRAueiK7E — Roll Call (@rollcall) April 5, 2017

Merkley’s protest was met with celebration from other Democrats on social media.

Thank you @SenJeffMerkley for speaking up tonight to filibuster Gorsuch’s disastrous nomination. #HoldTheFloor https://t.co/JZaqjnRqDO — Kamala Harris (@KamalaHarris) April 5, 2017

This article has been updated to reflect that Merkley ended his speech just after 10 a.m. ET on Wednesday.