The Oregon Democrat's marathon -- with a brief assist from Sen. Dick Durbin of Illinois early Wednesday morning — wrapped up shortly after 10 a.m. ET.
"I was hoping the message would reach a few hearts across the aisle that we're on a path we have not completed -- the seat has not been stolen, we're potentially a couple of days away from that," Merkley told reporters after he left the Senate floor.
Following his extended remarks, one reporter asked him which was harder: the talk-a-thon or the recent Ironman triathlon that Merkley completed.
"That's a good question," he said. "I tell you my feet really hurt standing in one place so this was more uncomfortable than the Ironman."
His talk-a-thon does nothing to stall a vote on Gorsuch because Senate Majority Leader Mitch McConnell had already taken the procedural step to lock in a time to vote to end debate over Gorsuch.
While Democrats have enough votes to carry out a true filibuster that actually would delay a vote, McConnell said Wednesday that Republicans, who hold a 52-48 majority, have enough votes to overcome that filibuster if they use the nuclear option
and move to a final confirmation vote Friday.
Merkley was one of the first Democrats earlier this year to pledge that his party would mount the filibuster, meaning he was confident they could get the 41 votes needed to sustain it.
No regrets for 2013 change
He was also an advocate for the use of the nuclear option by Democrats in 2013 when their party was in the majority and Republicans objected to some executive branch nominees and judicial nominations.
Republicans are now citing that rule change as a precedent for their potential use of it later this week. Merkley, however, said he had no regrets in pushing for the nuclear option nearly four years ago.
"That setting was one where we labored for the better part of year working with our Republican colleagues saying what you're doing in blocking all these executive nominees, all these judicial nominees. ... We can't have a situation where the filibuster is used to prevent the administration from fundamentally working," he said. "So we did the right thing."
Garland nomination blocked
On the floor, Merkley has argued that Gorsuch is not a mainstream nominee and blasted Republicans for blocking consideration of President Barack Obama's nominee of Merrick Garland
"For the first time in US history, a seat has been stolen from one president and delivered to another in a court packing scheme," Merkley said around 4 a.m. ET. "And if that were to succeed, it would set a precedent that will haunt the court for decades to come. And it will haunt this body, the Senate, because if a theft succeeds then it changes the analysis of every future Supreme Court vacancy."
He and other Democrats have also focused on individual cases in which they felt Gorsuch was unfair to the "little guy" and sided too often with government or corporations.
Republicans, hitting back against the argument that he's extreme, say Gorsuch sided with the majority in 99% of his opinions as a federal judge in the past decade, and the GOP said that of the 2,700 cases he has ruled on, 97% were decided unanimously.
Merkley made his closing argument shortly after 10 a.m. ET, also calling for the investigations into Trump's campaign ties to Russia to conclude before Gorsuch is further considered.
Following his remarks, Merkley went directly to the restroom. He gave the thumbs up to reporters after CNN asked how the senator was doing.