Supreme Court nominee Neil Gorsuch is making actor Mark Ruffalo very, very angry. And you won’t like him when he’s angry.

The 49-year-old Hulk actor and liberal activist took to his Twitter account Tuesday to urge fans and followers to call their Democratic representatives to filibuster President Trump’s pick to replace the late Justice Antonin Scalia on the Supreme Court.

“Call, call, & don’t stop calling,” Ruffalo wrote.

Daily Action: Urge Democratic Senators to stand united in favor of a Gorsuch filibuster. Call, call, & don't stop calling (844) 241-1141 & — Mark Ruffalo (@MarkRuffalo) March 28, 2017

The actor also thanked Sen. Chuck Schumer (D-NY) for “holding strong” on his own vow to filibuster Gorsuch.

.@SenSchumer thanks for holding strong on #FilibusterGorsuch called again today and lines were busy. — Mark Ruffalo (@MarkRuffalo) March 28, 2017

Will you be joining the filibuster? Will you be pressing your colleagues to do the same? https://t.co/4Zb3l8tLag — Mark Ruffalo (@MarkRuffalo) March 28, 2017

On Monday, Democrats on the Senate Judiciary Committee forced a one-week delay on Gorsuch’s confirmation vote. If Schumer attempts to filibuster Trump’s Supreme Court pick — as he indicated he would do last week — Gorsuch will need 60 votes for clearance to a simple majority vote, requiring eight Democrat votes in addition to 52 votes from Republicans.

Ruffalo has been a frequent critic of Trump’s administration.

In January, the actor and environmental activist joined fellow celebrities Alec Baldwin, Michael Moore and Robert De Niro at a pre-inauguration protest outside Trump Tower in Manhattan.

“Neo-liberalism is dead. Progressivism is alive, and we’re it,” Ruffalo said then. “We’re the people protectors. And this is heart work. That’s the only way. We need to protect our hearts. We need to lead from our hearts. We need to strengthen our hearts.”

Before the election, Ruffalo joined his Avengers castmates Robert Downey Jr. and Don Cheadle in a Joss Whedon-directed PSA that urged citizens to vote for former Democratic candidate Hillary Clinton over then-candidate Trump.

“Tell the world that you care about what happens to it,” he said in the video.

Follow Daniel Nussbaum on Twitter: @dznussbaum