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As the government shutdown nears its 40th day, Republican senators are balking at President Donald Trump’s demand to end the filibuster, a rule change that would allow a simple Senate majority vote to pass legislation instead of the 60 votes now required.

"We have to get the country open. And the way we're going to do it this afternoon is to terminate the filibuster," Trump told senators at the White House Nov. 5.

A filibuster is a procedure in which senators can talk on the floor for hours to delay action on a bill. Eliminating it would allow Republicans, with a 53-47 Senate majority, to pass, by partisan vote, bills that are favored by Trump. But that would last only as long as the GOP retains control of the Senate.

Republicans are hesitant to quit the procedure because Democrats could retake the Senate majority in future elections, and that would give them a bill-passing advantage.

Here is how Senate voting works, with and without the filibuster.

Republicans hold the most Senate seats

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Simply stated, the filibuster lets a minority number of senators block passage of a bill until 60 of 100 of the full Senate agree to limit debate on legislation – a process known as cloture – and allow passage to proceed.

How does the filibuster work?

In a filibuster, a senator or a group of senators can speak on the floor for hours on nearly any subject to prevent a vote.

Under Senate Rule XXII, 16 senators are required to file for cloture. A senator may interrupt a speaking senator on the floor to present the cloture motion.

At least 60 senators must vote for cloture to end the filibuster.

That means 60 votes are needed to conduct almost any Senate business. That’s because even common maneuvers, such as calling up a bill or recessing for the night, are subject to debate.

The Senate can keep working on other business even while it is filibustering a bill, according to the Pew Research Center.

What happens if senators vote to end debate?

If senators approve cloture, debate is restricted to another 30 hours. Then a final vote is conducted. At that point, a simple Senate majority is all that's needed for passage.

What happens if senators don’t end debate?

The senators can keep speaking, stalling the bill in the Senate.

What happens if the Senate ends the filibuster altogether?

If the Senate terminates the filibuster procedure, debate on legislation would be limited. Senators would have to decide on debate lengths.

The filibuster can be abolished with a contentious procedure known as the nuclear option. It happens when the Senate leader calls a vote and then asks the parliamentarian for a ruling on whether a filibuster is justified. If a majority votes to overturn the parliamentarian, that becomes precedent for future votes.

After that, the Senate would decide legislation by a simple majority vote, at least 51 of 100 senators, or having the vice president cast the deciding vote in a 50-50 tie.

The first use of the filibuster in the Senate was in 1841. It was officially adopted with a two-thirds vote requirement in 1917. The vote threshold was dropped to 60 in 1975. The nuclear option was used in 2013 to prevent filibusters for court nominations and executive branch positions and again in 2017 to decide Supreme Court nominations.

CONTRIBUTING Bart Jansen

SOURCE USA TODAY Network reporting and research; Reuters; senate.gov; congress.gov; Congressional Research Service; Pew Research Center

This article originally appeared on USA TODAY: How the Senate filibuster works, why Trump wants it ended, and why it likely will stay

Reporting by George Petras and Stephen J. Beard, USA TODAY / USA TODAY

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