Senate Minority Leader Charles E. Schumer announced Thursday that he will oppose Sen. Jeff Sessions‘ nomination to be the next attorney general.

“After reviewing his record and giving careful consideration to his answers during the hearing, I am not confident in Senator Sessions’ ability to be a defender of the rights of all Americans, or to serve as an independent check on the incoming administration,” the New York Democrat said in a statement.

[AG Pick Sessions Defends Record at Contentious Hearing]

Schumer also said he was “deeply concerned” by Sessions’ views on immigration. The Alabama Republican was vehemently opposed the 2013 comprehensive immigration bill that Schumer helped craft.

But Sessions has the vote of at least one Democrat after the confirmation hearings.

“Jeff Sessions has my vote. He’s my friend,” Sen. Joe Manchin III of West Virginia told Fox News. “Now, some people say he’s too conservative, well some people are too liberal. You know, the bottom line is President-elect Trump won the election. He ought to have a right to put his staff together.”

Schumer had previously raised concerns about Sessions’ views on immigration and protecting voting rights. But he withheld judgement until Thursday, after Sessions’ confirmation hearings this week.

In past statements, Schumer also noted the pair are friends and work out next to each other in the Senate gym.

“We’re on the bike next to each other oftentimes, watching “Morning Joe,” and making diametrically opposed comments about what’s going on the show,” Schumer said last week when asked about Sessions.

[ Booker, Lewis Challenge Sessions’ Commitment to Civil Rights ]

Sitting senators typically sail through the confirmation process, but other Democrats will likely oppose Sessions’ nomination. On Wednesday, Sen. Cory Booker, D-N.J., broke precedent by testifying against a fellow sitting senator’s Cabinet nomination. He said Sessions is not dedicated to protecting the civil rights of all Americans.

However, if Republicans remain united in support of Sessions, Democrats will not be able to block his confirmation. In 2013, Senate Democrats lowered the threshold for ending debate on most executive branch nominations, meaning confirmation only requires a majority of senators to support the nominee.

— Niels Lesniewski contributed to this report.