 -- Sen. Jeff Sessions has been confirmed as the new attorney general of the United States -- capping a contentious process that involved protests from his Democratic colleagues.

The Senate voted tonight 52-47 in favor of Sessions' confirmation. Sen. Joe Manchin of West Virginia was the lone Democrat to vote for confirmation, while Sessions himself voted present.

The Alabama Republican, 70, faced a contentious confirmation process. His nomination for the position had been strongly opposed by Democrats and civil rights groups since then-President-elect Donald Trump tapped him in mid-November. Many critics have cited concerns about past allegations of racism, his record on civil rights and immigration and his failure to be confirmed as a federal judge in 1986 as key points of contention.

Sessions attempted to address some of these concerns during his cabinet hearing in early-January. Speaking to allegations that he had made racist remarks decades ago as Alabama attorney general, Sessions said, "I hope my tenure in this body shows you that the caricature of me wasn't accurate. It wasn't accurate then, and it's not accurate now."

His reputation and qualifications for the attorney general post were also defended by a number of his Republican colleagues.

"He is a man of honor and integrity, dedicated to the faithful and fair enforcement of the law, who knows well and deeply respects the Department of Justice and its role," Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa, said in his opening remarks.

Minutes after his colleagues confirmed him to be the next Attorney General, Sessions took to the floor to thank them and deliver his last remarks.

"I can't express how grateful I am for all of you who stood by me during this difficult time,” he said, alluding to the fight Democrats staged against his nomination.

Sessions said he appreciates the "full debate" the Senate had and thanked those who "found sufficient confidence" in him to cast their vote.

While on the floor, Sessions also delivered his letter of resignation, which he will also deliver to Alabama Gov. Robert Bentley.

The president took to Twitter to congratulate Sessions on his confirmation as Attorney General.

The two days of hearings were marked by intense grilling from Democrats and numerous interruptions by protesters. Sen. Cory Booker, D-N.J., and Rep. John Lewis, D-Ga., both testified against Sessions.

"Those who are committed to equal justice in our society wonder whether Sen. Sessions' call for 'law and order' will mean today what it meant in Alabama, when I was coming up back then," Lewis said in his testimony. "The rule of law was used to violate the human and civil rights of the poor, the dispossessed, people of color."

Democrats were successful in delaying the Senate Judiciary Committee vote on Sessions once. Before tonight's floor vote, they held around-the-clock speeches in opposition to his confirmation.

ABC News' Ali Rogin, Mike Levine and Julia Jacobo contributed to this report.