By Lawrence Hurley and Andrew Chung
WASHINGTON (Reuters) - As a grueling U.S. Senate confirmation hearing for Supreme Court nominee Neil Gorsuch finishes on Thursday, the spotlight turns to whether he will gain the support of vulnerable Democratic senators who are up for re-election in 2018.
They hold the key to whether the 100-member Senate, where Republicans hold 52 votes, can avoid a prolonged floor fight over President Donald Trump's high court nominee and whether confirming Gorsuch becomes an early major win for Trump as president.
If at least eight Democrats join the 52 Republicans and back Gorsuch, that will provide the 60 votes needed to pass a procedural motion letting the Senate move quickly to an up-or-down vote on his nomination, with only a simple majority for approval.
If the Democrats deny Gorsuch those eight votes, a more embattled scenario could unfold, with potential to change how the Senate handles Supreme Court nominees.
As of late on Wednesday, it was unclear what Democrats would do, but conservative activists had identified 10 possible 'yes' votes for Gorsuch among Democrats seeking re-election next year in states that Trump won in the 2016 election.
They include West Virginia's Joe Manchin and Florida's Bill Nelson, both undecided on Gorsuch, their spokesmen told Reuters.
Another, Tammy Baldwin of Wisconsin, opposes the nomination, a spokesman said. Bob Casey of Pennsylvania said he would announce his intentions on Thursday morning.
Another vote potentially up for grabs is that of Michael Bennet, a Democrat from Gorsuch's home state of Colorado. He is not up for re-election next year and his state voted for Democrat Hillary Clinton in the 2016 election. He introduced Gorsuch to the Judiciary Committee on Monday, but did not commit to supporting the nomination, saying he was keeping an "open mind."
Bennet's office did not respond to a message seeking comment on whether he had decided yet.
Democratic Senate leader Chuck Schumer has said Gorsuch should have to get 60 votes to secure his confirmation, but it was unclear whether Democrats would remain unified and attempt to block a final vote, as liberal activists would like.
If Gorsuch is confirmed, he would restore a 5-4 conservative majority on the Supreme Court, a key goal of Republicans.
In three days of testimony before the Senate Judiciary Committee, Gorsuch, a federal appeals court judge, remained calm under sharp questioning from Democrats, paving the way for the panel to vote on the nomination on April 3.
The hearing will conclude on Thursday with testimony from outside witnesses. Senate Republican leader Mitch McConnell has said he wants the full Senate to have a final vote on the nomination before the chamber recesses on April 7.
Gorsuch is assured of support from the 52 Republicans. But the Senate requires confirmation of Supreme Court justices by the 60 votes needed to pass a procedural motion to block a "filibuster" effort to block a nomination.
If the Senate's Democrats stand together and filibuster Gorsuch, Republicans could reach for the "nuclear option" and change the Senate rules to allow confirmation by a simple majority vote. Some senators are reluctant to take such a step.
Several Democrats on the Judiciary Committee, including senior member Dianne Feinstein, told Reuters they would not comment on whether they would support a filibuster attempt.
Click http://tmsnrt.rs/2nANgEj for graphic on confirming Gorsuch
(Additional reporting by Julia Edwards Ainsley, Dustin Volz and Timothy Gardner; Editing by Kevin Drawbaugh and Peter Cooney)