Sen. Cory Booker (D-N.J.) will testify against his colleague, Sen. Jeff SessionsJeff SessionsBooker will attend inauguration Mega-mergers poised to get green light under Trump WHIP LIST: How many Dems will back Sessions? MORE, during Wednesday's confirmation hearing for President-elect Donald TrumpDonald Trump Martin Luther King's daughter: 'God can triumph over Trump' Trump: Monday will be day one of administration Trump's navy build-up comes with steep price tag MORE's attorney general pick.
Booker said Monday night he does not "take the decision lightly" to speak against a fellow senator, but he believes the Alabama Republican's positions on a myriad of issues are "deeply troubling."
"Senator Sessions’ decades-long record is concerning in a number of ways," said Booker. "The Attorney General is responsible for ensuring the fair administration of justice, and based on his record, I lack confidence that Senator Sessions can honor this duty."
The New Jersey Democrat, who is black, explained the unprecedented step by pointing to Sessions's opposition to a bipartisan criminal justice reform bill that Booker has been involved with since joining the Senate, as well as his views on reforming drug policy, his opposition to comprehensive immigration reform and his "failure to defend" minority groups, women and LGBT Americans.
Booker will speak before the committee on Wednesday along with Reps. John Lewis (D-Ga.) and Cedric Richmond (D-La.), the chairman of the Congressional Black Caucus, according to a release from the Senate Judiciary Committee.
Booker's office also announced his — who is the subject of early speculation as a potential 2020 president candidate — plan on Twitter.
It's unlikely that Democrats will be able to block the Sessions nomination. Under the 2013 "nuclear option," most nominees only need a simple majority vote to clear the upper chamber.
Republicans have a 52-seat majority. Moderate GOP Sen. Susan CollinsSusan CollinsSchumer puts GOP on notice over ObamaCare repeal 9 GOP senators Trump must watch out for Trump could alter Supreme Court for decades to come MORE (Maine) is one of two senators introducing Sessions at his confirmation hearing.
Though Sessions is well-liked by his colleagues, Democrats have pledged for months to fight his nomination. They've raised questions about whether Sessions would be able to apply the law equally to all Americans and if he'll be able to say no to Trump.
Sen. Sherrod BrownSherrod BrownTrump, House GOP could clash over 'Buy America' Four takeaways from Carson's confirmation hearing Carson: Don’t ‘pull the rug out’ on ObamaCare without replacement MORE (D-Ohio), noting Booker's involvement in the nomination, became the first senator to officially say he would vote against Sessions.
"You don't vote for somebody just because he's a Senate colleague and you have something called Senatorial courtesy," he told MSNBC. "You vote based on, not even entirely his past, you vote on his future and what an attorney general for the next four years is going to do."
Sessions's confirmation hearing comes roughly 30 years after his nomination for a federal judgeship was torpedoed by allegations of racism, which Sessions has repeatedly denied.