Faced with a solid majority of conservative justices on the Supreme Court for the first time in decades, a number of Democratic presidential candidates have said they’re open to increasing the number of seats on the court or establishing term limits for the justices, in an effort to dilute the conservatives’ power. Pete Buttigieg, for example, proposed a plan that would increase the number of Supreme Court justices to 15 in an attempt to balance the court ideologically. Other candidates, like Beto O’Rourke, have called for term limits.

These proposals haven’t been especially prominent in the primary so far, but a new poll from the Pew Research Center shows that Democrats’ views of the court are at their lowest point in more than two decades — signaling that primary voters could be in the mood for more talk about radical changes.

The Supreme Court is often regarded as the one branch of government that’s above the messy business of partisan politics. And 62 percent of respondents in the Pew survey did say they have a positive outlook on the court — much higher than favorability ratings for Congress or either of the two political parties. But Americans’ views of the Supreme Court have grown somewhat less favorable over time, and in the past few months, an unusually large partisan gap has opened up.

As the chart below shows, the share of Democrats who have a favorable outlook on the court plummeted from 63 percent in January to 49 percent today. Favorability among Republicans also took a small dip this year, but they’ve recently warmed to the court — as recently as July 2015, only 33 percent of Republicans had a favorable view of the court compared with 75 percent today.

And even though Republicans and Democrats’ views of the court are fairly malleable, and tend to shift around big events or decisions, an uptick in partisan rancor could prompt the justices to tread carefully in a year when the justices will already be addressing hot-button issues like President Trump’s effort to end Obama-era protections for young undocumented immigrants and workplace discrimination based on sexual orientation. “A 26-point gap between the parties is jarring — this seems like a fairly unprecedented situation,” said Michael Salamone, a political science professor at Washington State University who studies public responses to the Supreme Court. “If entrenched partisan views of the court persist, it could have a longer-term impact on the court’s legitimacy,” he added.

This isn’t the first time a political rift has emerged around the court. In the 1930s, Franklin Delano Roosevelt famously grew frustrated with the justices’ rejection of his New Deal policies and sparked a political firestorm by trying to add as many as six new seats. Several decades later, “Impeach Earl Warren” signs popped up in response to the liberal chief justice’s decisions on desegregation. And Richard Nixon explicitly ran against Warren court rulings that had expanded criminal defendants’ rights, including the landmark Miranda decision, in his 1968 campaign.

Historically, however, none of these episodes have fundamentally undermined the public’s faith in its legitimacy as an institution. Some scholars have argued that this is in part because when the court gets too far outside the mainstream, the justices usually back down. As I wrote for FiveThirtyEight last year, there is plenty of evidence that the justices, despite their lifetime appointments and seemingly unlimited power, do bend to the winds of public opinion. One study, for instance, found that the court’s overall ideological tilt generally tracks with the public’s over time. Tom Clark, a political science professor at Emory University who studies the Supreme Court and public opinion, said that talk about court-packing among the Democratic candidates could send a signal to the justices that a significant chunk of the public is unhappy with its rulings.

So one question, as the primary progresses, is whether the Democratic candidates will focus more on reforming the court. According to Pew, the court’s favorability is particularly low among liberal Democrats, which could make court-packing a popular issue among primary voters. But proposing to overhaul the structure of a branch of government is also no small thing. A study of Roosevelt’s bid to pack the court found that most voters were skeptical of his plan, even if they didn’t like what the justices were doing. And a Fox News poll conducted in April found that 51 percent of Americans oppose increasing the number of justices on the court.

But the deep partisan split in how the court is viewed could still affect how the justices operate, at least while the presidential election unfolds. “I think they’ll want to keep their docket as boring as possible, to avoid the spotlight,” Salamone said. Staying under the radar could be difficult, though, given that the court already has several high-profile cases lined up. And with a case involving abortion rights also on the horizon, the partisan divide could deepen even further.