Updated 2:45 p.m. ET

Senate Democrats now have enough votes to block the Supreme Court nomination of Judge Neil Gorsuch under current Senate rules, which require 60 votes to proceed on a nomination.

That sets up a showdown later this week that will likely lead to a reinterpretation of Senate rules, so that the nominations of Supreme Court justices can be advanced with 51-vote majorities, rather than the preliminary 60-vote threshold that has long applied to high court nominations.

"If we have to, we will change the rules," Republican Sen. Lindsey Graham of South Carolina said during Monday's Judiciary Committee meeting. "It looks like we're going to have to."

Graham's comment came after two senior Democrats on the committee, Sen. Dianne Feinstein of California and Sen. Patrick Leahy of Vermont, said they'd vote no on cloture for Gorsuch. They were seen as Senate traditionalists who may have voted yes, at least for the preliminary vote, in order to avoid what's long been known as "the nuclear option."

Sen. Mark Warner of Virginia also announced Monday he'd oppose Gorsuch in a cloture vote. Sen. Chris Coons of Delaware was the 41st Democrat to announce a "no" vote on cloture, doing so during the Judiciary Committee meeting.

The Judiciary Committee voted 11-9 on Monday to advance the Gorsuch nomination to the full Senate, with all Republicans voting for Gorsuch and all Democrats voting against him.

Now that a "nuclear" showdown appears inevitable, here's how the rest of the week will likely play out:

There's a two-step process on the Senate floor. The key is a procedural vote expected Thursday to end debate on the nomination. That's known as a "cloture vote" and with at least 41 Democrats voting no, the motion to proceed to a final vote will fail.

But at that point, Senate Majority Leader Mitch McConnell would be expected to change the rules that govern the Senate through a series of procedural votes. In the past, enough senators in the majority party have been leery of this rules change to avoid it. But it's clear McConnell would have the votes he needs to invoke the "nuclear option," and while he has not specifically said he will do so, his declarative comments about getting Gorsuch confirmed this week make it clear that McConnell is prepared to make this move.

If McConnell were to do so, a second cloture vote would then happen, but at this point, only 51 votes would be needed to end debate and move to a final vote. These are the rules that governed President Trump's Cabinet confirmations, since Democrats changed cloture rules in 2013 for everything but the Supreme Court.

The Senate would then proceed to 30 hours of debate, which is expected to go overnight Thursday into Friday. There will then be a final vote to confirm Gorsuch on Friday, which — after the rules change — would require only a simple majority of 51 senators.

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