President Donald Trump on Saturday announced Judge Amy Coney Barrett as his pick to replace the late Justice Ruth Bader Ginsburg on the Supreme Court. Now Democrats have less than 40 days to try to stop her appointment before the Nov. 3 election.

Trump has already said he wants a ninth justice in place because he believes the Supreme Court will decide the election, given legal challenges over ballot counting. The Senate Judiciary Committee reportedly plans to move forward with confirmation hearings on Oct. 12, and Senate Majority Leader Mitch McConnell (R-Ky.) said earlier this week that he will hold a floor vote for the nominee before the election.

There aren’t many options available to keep this from happening. But progressive activist groups and, increasingly, members of the party’s elite are pushing Senate Democrats to deploy every tool available to fight this nomination. Democrats are also being urged to threaten retribution for this appointment, if it comes to pass, in the form of adding justices to the Supreme Court and eliminating the legislative filibuster.

The next few weeks will set the stage for what kind of change will be possible for the foreseeable future. Since the Supreme Court has assumed the role of final arbiter in America’s political system, a sixth conservative justice would shift the court to the right on abortion rights, government regulation of corporations, campaign finance regulation and voting rights laws. Any federal government regulatory action to deal with climate change could be at threat ― as would the right to choose, antitrust actions to unravel corporate monopolies, and limits on campaign contributions made by the wealthy and corporations. It would be a seismic, generational shift.

Trump’s replacement of Ginsburg before the election, or during the lame-duck period if he loses the election, would be “illegitimate,” according to former Attorney General Eric Holder. Holder said Democrats should promise to add justices to the court if they win the presidency and the Senate in November.

“Everything should be on the table,” Sen. Elizabeth Warren (D-Mass.) said on Monday.

Senate Democrats have already made their first move to slow down the chamber’s operation. On Tuesday afternoon, Democrats invoked the “two-hour rule,” which limits the time when committees may hold hearings while the full Senate is in session. The move caused some committees to postpone their hearings on Tuesday.

“Justice Ginsburg’s dying wish was that she not be replaced until a new president is installed. Republicans are poised to not only ignore her wishes, but to replace her with someone who could tear down everything that she built,” Senate Minority Leader Charles Schumer (D-N.Y.) said in a statement on Saturday, vowing to oppose the nomination. “This reprehensible power grab is a cynical attack on the legitimacy of the Court.”

The move to invoke the two-hour rule suggests Schumer is willing to go to the mat to stop or slow this nomination ― and, if that fails, to make McConnell and Republicans pay for the hypocrisy of pushing to confirm a new justice four years after McConnell invented a rule that ‘forbade’ him from considering then-President Barack Obama’s nomination of Judge Merrick Garland.

While McConnell claims to have the support of at least 51 members of his caucus to bring the nomination to the floor for a vote before the election, he has also already lost the votes of Republican Sens. Lisa Murkowski (Alaska) and Susan Collins (Maine). Could more senators decide against the nomination if the process drags on past an election where the Democratic nominee, former Vice President Joe Biden, wins?

“We can’t let ourselves fall into this Mitch McConnell play,” Christopher Kang, chief counsel for the progressive judicial group Demand Justice, said.

“[The] public sentiment, it sort of feels to me a lot like the health care fight, where we just have to keep fighting this and you never know what’s going to happen,” Kang said. “You never know where you’re going to have the moment of impact.”