Watch Cory Booker explain why he's taking unprecedented measures to fight Jeff Sessions

Sen. Corey Booker (D–NJ) has announced that he will take the stand to testify against his colleague Jeff Sessions (R–NJ) during the confirmation hearing for Sessions’ nomination for Attorney General.

According to Booker’s staff, no sitting senator has ever attempted to block the nomination of another sitting senator by testifying against them.

“I’m breaking a pretty long Senate tradition,” Booker explained to MSNBC’s Chris Hayes on Monday evening. “Please understand, I think these are extraordinary times. And I think they call for extraordinary measures.”

Rep. Chris Collins dismissed Booker’s unprecedented decision as a “stunt,” telling the hosts of CNN’s New Day that, “what Cory Booker is doing is nothing but self-serving grabbing headlines.”

Democratic Reps. John Lewis  and Cedric Richmond are also scheduled to testify against Sessions’ nomination—a process that is likely to bring up Sessions’ history of alleged racism and discrimination. Booker’s announcement comes after fellow Democratic Sen. Sherrod Brown became the first senator to officially declare his intent to vote against Sessions’ nomination.

Speaking with MSNBC, Booker elaborated on his decision to testify against Sessions’ nomination, explaining it as more than simply seeing his colleague as unfit for the job.

“We’ve seen Jeff Sessions — that’s Senator Jeff Sessions — consistently voting against or speaking out against key ideals of the Voting Rights Act, taking measures to try to block criminal justice reform,” Booker said. “He has a posture and a positioning that I think represent a real danger to our country.”