At least 41 Democratic senators have publicly committed to filibuster President Trump’s Supreme Court nominee Neil Gorsuch, leading to a probable showdown with Republican Senate Majority Leader Mitch McConnell.

The filibuster might seem like payback for Democrats after Republicans refused to consider the nomination of then-President Obama’s Supreme Court nominee, Merrick Garland, for 293 days starting last year. Unlike Republicans last year, however, Democrats don’t have all that much power. They aren’t in the majority — and McConnell has strongly hinted that he could seek to eliminate the filibuster for Supreme Court picks if Gorsuch can’t get 60 votes. Across a variety of surveys, moreover, a plurality of voters think the Senate should confirm Gorsuch, although a fair number of voters don’t have an opinion either way. Therefore, Democrats’ political endgame is unclear.

Gorsuch is quite unpopular with liberal voters, however: by a 61-15 margin, they oppose his confirmation, according to a YouGov poll last week. Thus, the planned filibuster may simply be a sign of the liberal base’s increasing influence over the Democratic coalition. The share of Democrats who identify as liberal has steadily increased over the past 10 years. According to the recently released Cooperative Congressional Election Study, 53 percent of Democratic voters identified as liberal last year. Until recently, it was rare to find surveys that showed liberals made up a majority of the party.