WASHINGTON (AP) — Seemingly frustrated by the government shutdown and Democrats’ unwillingness to accept a Republican funding bill, President Donald Trump is once again demanding that the Senate eliminate the legislative filibuster.

The filibuster is a longstanding parliamentary tool that halts action on most bills unless 60 senators in the 100-member chamber vote to move forward. Over the years, it has stymied policy priorities for Democrats and Republicans alike, and Trump has been complaining about the maneuver since his first White House term.

Getting rid of it would be a way for Republicans to immediately end the now month-long shutdown, he said. “It is now time for the Republicans to play their ‘TRUMP CARD,’ and go for what is called the Nuclear Option — Get rid of the Filibuster, and get rid of it, NOW!” the president wrote on his social media site Thursday night.

But majority Republicans have strongly resisted calls to eliminate the legislative filibuster, since it would dilute their power if and when they are in the minority again. In its best form, the filibuster encourages compromise and dealmaking.

As with any government funding bill — and most other legislation — Republicans need help from at least a handful of Democrats to clear the 60-vote threshold in the Senate since they control just 53 votes. In exchange for their votes on a stopgap funding bill, most Democrats have been demanding an extension of subsidies for people who purchase health coverage under the Affordable Care Act. Republicans say that’s a costly nonstarter, especially on a bill that keeps the federal government operating for a mere seven weeks.

Democrats argue that because the Senate needs 60 votes to advance funding bills, that gives them leverage. As the shutdown drags on, frustrated Republicans have been floating the idea of getting rid of the filibuster in order to erase that leverage. “Maybe it’s time to think about the filibuster,” said Sen. Bernie Moreno, R-Ohio, on Fox News earlier this month.

Unlike many other demands from Trump, GOP senators have generally resisted his calls to get rid of the filibuster. Senate Majority Leader John Thune has long defended the filibuster, emphasizing that it is essential to the Senate's identity and legislative process.

Despite Trump's insistence and pressure from House Republicans, the majority of GOP senators appear committed to preserving the filibuster as a means of ensuring bipartisan cooperation and protecting fundamental legislative principles.