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.