Vice President Joe Biden (D) said during an interview with Rachel Maddow on Thursday night that the Senate is balking at filling the Supreme Court’s vacant spot because “they’re intimidated by” their party’s extreme members.

“I think it’s the tail wagging the dog,” Biden added.

In his time in the Senate, Biden presided over five confirmation hearings for the Supreme Court, including Associate Justice Clarence Thomas.

“I think the leadership went out to make sure they got out ahead of (Sen.) Ted Cruz,” Biden said. Cruz, who led the effort to shutdown the government in 2013, said he would filibuster any nomination from President Barack Obama.

“I don’t believe in their heart they think this makes sense. We’ve never done this before,” Biden told Maddow from St. Paul, Minnesota.

The confirmation process is time-intensive and must start soon, he said.

“If we don’t start, if we don’t nominate someone in the next month or so, start the hearing process—and they say nothing’s going to happen until the next election—it won’t be until next June or July before you have a Supreme Court justice,” Biden said. “We have a dysfunctional Congress now. We don’t need an institutionally dysfunctional Supreme Court.”

Here’s the full interview.

Watch the clip, from MSNBC, below: