Vice President Mike Pence is heading back from New York to Washington, D.C,. on Air Force Two Friday to be in place to the tiebreaking vote to confirm Brett Kavanaugh to the Supreme Court.

White House sources confirmed that Pence would be in Washington throughout Saturday and Sunday with his schedule cleared so he could be whisked by motorcade from his Naval Observatory residence to Capitol Hill at short notice.

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The Senate voted 51-49 to end debate on Kavanaugh Friday morning, setting up a dramatic final vote on the nominee Saturday.

The GOP whip count has Kavanaugh narrowly making it through by the same margin as Friday's vote, but a last-minute defection from one senator would place Kavanaugh's fate in the hands of the vice president.

Sen. Lisa Murkowski, R-Alaska, who voted against Kavanaugh Friday, announced Friday she will vote against Kavanaugh when the Senate convenes to formally vote on his nomination Saturday. Her "no" vote sets up a situation where Republicans can only withstand one more defection. If two more senators come out against Kavanaugh, his nomination is dead.

Sen. Susan Collins, R-Maine and Sen. Jeff Flake, R-Ariz., voted to move forward with Kavanaugh's nomination Friday. While the vote is a strong signal Kavanaugh is on the verge of being confirmed, the "yes" votes from Collins and Flake don't necessarily mean they will support him in the final vote.

All eyes are on Collins, who will announce whether or not she plans to vote for Kavanaugh at 3 p.m. Friday. For his part, Flake has said he will vote in favor of Kavanaugh Saturday, barring some "big" change that sways his opinion.

Sen. Joe Manchin, D-W.Va., voted with Republicans Friday in favor of moving forward with Kavanaugh. He is expected to make a formal statement, but his "yes" vote Friday could be a sign he will vote to confirm Kavanaugh.

[Last undecided Democrat Joe Manchin still reviewing FBI’s Kavanaugh report]

If Manchin or Collins votes against Kavanaugh, Pence, acting as the president of the Senate, would need to cast the deciding vote to confirm the nominee.

Pence has acted as the tiebreaking vote some nine times during the first two years of President Trump's administration. In January this year, he acted as the tiebreaker to confirm former Kansas Gov. Sam Brownback's nomination to serve as ambassador-at-large for international religious freedom.

The vice president also cast the deciding vote to confirm Secretary of Education Betsy DeVos - the first-ever tiebreaking vote on a cabinet nominee.

Pence would be the first vice president to have to vote to break the tie for a Supreme Court nominee. The office of Senate Majority Leader Mitch McConnell, R-Ky., told the Washington Examiner Friday afternoon that the plan is to vote on Kavanaugh's nomination under regular order Saturday evening.