Sen. Catherine Cortez Masto of Nevada just became the latest Democratic senator to come out in support of reforming the 60-vote threshold on legislation. A member of the establishment wing of the party, Cortez Masto chaired the Democratic Senatorial Campaign Committee during the 2020 election cycle.

Sens. Amy Klobuchar and Tina Smith of Minnesota similarly endorsed reforming or eliminating the filibuster in the past week, adding to the momentum.

That centrist rank-and-file Democrats are increasingly calling for a major Senate rule change is a huge deal. It shows the party itself is rapidly changing on an idea that had large bipartisan opposition as recently as a few years ago. In 2017, for example, 33 Democrats signed a letter authored by Sen. Susan Collins (R-Maine) reaffirming the rights of the minority via the legislative filibuster. Some of those Democratic senators are now opening the door to future reforms.

“It’s important we respect the rights of the minority but if you continue to see in some of these states dramatic cutbacks on voting rights… you can’t take any remedy off the table,” Sen. Mark Warner (D-Va.), who signed the 2017 letter, told HuffPost on Tuesday. “But I still, perhaps naively, have hopes for bipartisanship.”