Doug Jones, the first Alabama Democrat to be elected to the Senate in 25 years, was sworn in on Wednesday by Vice President Mike Pence.
Jones, 63, was voted in during a special election last month in the deep-red state, defeating former state justice Roy Moore, whose campaign was dogged by allegations that he groped teenage girls decades ago when he was in his 30s.
Former Vice President Joe Biden escorted Jones to the Senate floor for the ceremony.
Jones, who will narrow the Republican Party’s majority in the chamber to 51-49, was one of two Democrats sworn in Wednesday.
Minnesota Lt. Gov. Tina Smith, who was named to replace Al Franken — who resigned last month over accusations of sexual misconduct — also took the oath of office.
In an interview early Wednesday on Capitol Hill, Jones told reporters he plans to be a “good senator” and “a bipartisan.”
Jones defeated Moore, 70, in a special election Dec. 12 to fill the seat vacated by Jeff Sessions when he became President Trump’s attorney general.
Despite winning by nearly 22,000 votes, Jones wasn’t certified the winner until Dec. 28 because Moore filed a lawsuit claiming election fraud.