Alabama Republican Sen. Jeff Sessions is poised to clear his first Senate hurdle Tuesday morning on his way to becoming head of the Department of Justice — a role thrown into sudden upheaval hours after the firing of the acting attorney general.

But before his nomination makes it before the full Senate, a hearing for the Senate Judiciary Committee to vote could last longer than usual as Democratic committee members unleash against President Donald Trump’s immigration-related executive order being widely criticized as a ban against Muslims.

Related: Sessions Once Told Yates: You Have ‘to Say No to President’

Sen. Patrick Leahy of Vermont, the ranking Democrat on the committee, is leading a vote to block Sessions, calling into question his civil rights record, hard-line immigration stance and ability to enforce the nation’s laws independently from what the White House would want.

“I have serious doubts that Sen. Sessions would be an independent Attorney General,” Leahy said in a statement Monday. Sessions was the first Senator to endorse Trump’s candidacy for president.

During two days of hearings earlier this month, Sessions denied decades-old racism charges against him, including that he sympathized with the KKK. Those charges cost him a seat on the U.S. District Court for the Southern District of Alabama in 1986 after being nominated by President Ronald Reagan.

“These are damnably false charges,” Sessions said this month.

The Senate Judiciary Committee was meeting at 9:30 a.m. ET before Sessions’ nomination goes before the full Senate. There, he would need a simple majority to approve him, and since Republicans control the majority of the Senate with 52 seats, he is expected to win confirmation.

Acting Attorney General Sally Yates, who was fired by Trump on Monday for refusing to enforce his immigration ban, has been replaced by Dana Boente, the U.S. Attorney for the Eastern District of Virginia.