WASHINGTON Many Democrats say they oppose changing Senate rules to eliminate the 60-vote threshold on legislation, otherwise known as the filibuster , despite some calls from the left urging them to do so to more easily advance their agenda in 2021.

Ambitious Democratic proposals like Medicare for all or the Green New Deal stand little chance of becoming law in the near future given near-unanimous Republican opposition and the Senates long-standing supermajority requirement. Even if Democrats manage to claw back to power in the Senate and recapture the White House in 2020, the GOP would likely prevent them from advancing to a final vote by using the filibuster.

Thats why some on the left are pushing Democrats to either be honest with voters about the chances of passing major legislation theyve introduced or simply rip the Band-Aid off and ditch a rule that doesnt actually appear in the Constitution anyway.

The Founders invented the Senate as a majority-rule body. The supermajority threshold is a 20th-century mutation. [Senate Republican leader Mitch McConnell] will deny any Dem POTUS 60 votes on everything. If Dems win the WH & Senate in 2020, they should nuke the 60-vote threshold on day one and get on with it, Adam Jentleson, a former spokesman for ex-Sen. Harry Reid (D-Nev.), said last month.

Other progressives like Brian Fallon of the advocacy group Demand Justice have argued that Democrats stand to benefit more from eliminating the filibuster because Republicans are generally less likely to propose sweeping changes in domestic policy due to their conservative ideology.

But nearly a dozen Democrats rejected those arguments in interviews on Capitol Hill on Tuesday, calling the filibuster a critical tool that helps foster bipartisanship, as well as a means of guarding against political passions that can bubble up in the House and the executive branch. Many of those Democratic senators also expressed concern about a scenario in which Republicans once again controlled both Congress and the White House.

If last year we did not have the filibuster, the Trump administration and the GOP majority could have rammed through an incredible range of laws that those same progressive groups would find incredibly destructive to the nation. So while I understand the frustration ... I think the consequences of getting rid of it are too great, Sen. Chris Coons (D-Del.) said Tuesday.

Indeed, if the filibuster had not been on the books during the first two years of Donald Trumps presidency, Republicans could have passed a whole host of legislation Democrats most likely would not liked to have seen become law including, possibly, funding for his border wall.

What you might think today would be in your favor, might not be in your favor tomorrow, Sen. Jacky Rosen (D-Nev.), who was just elected to a six-year term, added on Tuesday.

Some Democrats still harbor regrets over the decision in 2013 to unilaterally end the filibuster for executive and judicial nominees. Democratic leaders said at the time they were forced to take the step to confirm a number of President Barack Obamas nominees given unprecedented GOP obstruction from people like McConnell. Reid, who pulled the trigger on the rule change, still maintains that it was the right thing to do . But now that Republicans are confirming young, conservative judicial nominees at a historic pace under the Trump administration, some Democrats say there is reason for caution about going even further.

I would remind people there was a lot of interest in getting rid of the filibuster for judges and for the Supreme Court, and that has not served us well, Sen. Jeanne Shaheen (D-N.H.) told HuffPost on Tuesday when asked whether she supported eliminating the filibuster on legislation.

Many 2020 Democratic presidential hopefuls also share concerns about going nuclear to kill the filibuster. Sen. Cory Booker (D-N.J.), the most recent entry in the field, said last week he would personally resist efforts to get rid of it . Sen. Kirsten Gillibrand (D-N.Y.), meanwhile, said last month she would consider ending the filibuster. In the meantime, the presidential candidate said that lacking 60 votes means you havent done enough advocacy and you need to work a lot harder.

Sen. Bernie Sanders (I-Vt.), a potential White House contender, has endorsed several progressive proposals on health care and climate change. He has also recently introduced legislation that would drastically expand the estate tax on the wealthy , a proposal he says would would raise $2.2 trillion. But the senator declined to address how to go about getting such proposals passed into law on Tuesday.

Its a little bit speculative. I need to worry about whats happening in the country right now. Thats a little bit into the future, Sanders said when asked whether he supported killing the filibuster.

Sen. Elizabeth Warren (D-Mass.), meanwhile, was the only 2020 Democratic presidential hopeful who did not rule out the prospect of going nuclear in a Democratic-controlled Senate.

Everything stays on the table. You keep it all on the table. Dont take anything off the table, Warren said in an interview with Politico last week .

The debate over the filibuster is likely to heat up in the Democratic primary over the next two years with many progressives in the race floating a wish list of progressive proposals on everything from health care and taxes, to voting rights and climate change. But some Democrats think the conversation isnt exactly productive for the party when it comes to running Washington.

Some of us have to think about governing. ... In terms of nuts and bolts, in terms of making this place work better, I dont think that talk is helpful, Sen. Martin Heinrich (D-N.M.) told HuffPost on Tuesday, noting he was not running for president.

The likelihood of ending the 60-vote threshold on legislation is extremely small in the near future due to bipartisan opposition. Trump repeatedly pushed McConnell to kill the filibuster last year in order to build the wall, for example. The Kentucky senator has resisted the presidents entreaties, estimating in an interview last year that two-thirds of his caucus oppose doing so.

I dont think the legislative filibuster, which has been around for a long time, is a problem. And it does, I think, generate on many occasions kind of a bipartisan solution, and I dont think thats always bad for the country, McConnell said in the interview.

Still, progressives dont view the threat of a filibuster as an impediment to proceeding with legislation like Medicare for all. In fact, they argue that building political support for big new ideas often takes time, and the traditional place where that has occurred in the past is in the lower chamber.

With any kind of movement, especially with one as I think is very much needed like Medicare for all or any sort of universal health care, all of those movements start somewhere, and its got to start in the House, freshman Rep. Rashida Tlaib (D-Mich.) told HuffPost on Tuesday, noting the new Democratic majority will soon hold the first hearings on Medicare-for-all legislation.