Progressive organizations are attempting to change the Supreme Court by proposing term limits and the addition of two new justices.

The Progressive Change Institute, Be a Hero, Friends of the Earth, Presente and 350 have signed onto the idea, along with Take Back the Court, Demand Justice and the Sunrise Movement.

“Trump and the Republicans in Congress have used aggressive tactics, including eliminating the filibuster, to pack the courts with conservative ideologues and prevent the will of the people from being heard,” Erich Pica, president of the environmental group Friends of the Earth, told Politico. “From the fight for racial justice to efforts to stop climate change and protect our clean air and water, the current configuration of the court has consistently stood in the way of progress. We simply do not have a generation’s worth of time to replace judges.”

In a memo from the organizations supporting the idea, Republicans were accused of “manipulating the size of the court by refusing to consider President Obama’s nominee [Merrick Garland] for an open seat (and indicating that they would leave the seat open if Hillary Clinton won the 2016 election), then promptly changing Senate rules to fill the seat with a bare majority, rather than the previously-required 60 votes, when Trump took office.”

The memo also noted that the majority of recent Supreme Court justices were nominated by a Republican president, some of whom lost the popular vote.

“[Fifteen] of the last 19 Supreme Court justices were nominated by Republicans, despite the fact that Republicans have lost the popular vote in six of the last seven presidential elections,” the letter reads. “Four of the five conservatives currently on the court were appointed by Republicans who took office despite losing the popular vote.”

While the proposal has gained some traction, Democratic nominee Joe Biden has said he does not back it.

“I would not get into court packing,” he said a debate last year. “We had three justices. Next time around, we lose control, they add three justices. We begin to lose any credibility the court has at all.”