"I do," Burris said with a grin as Vice President Dick Cheney administered the oath of office to the former Illinois attorney general who takes Obama's place as the Senate's only black member.

More than a week after his colleagues were sworn in, Burris was seated without objection or a roll call vote, even though Majority Leader Harry Reid had said senators would have their voices heard on whether to accept his appointment.

Reid smiled broadly and applauded as Burris received a standing ovation from his new colleagues and accepted handshakes and congratulations from Republicans and Democrats alike. Later, the senior senator from Illinois, Dick Durbin, was throwing a reception in his new colleague's honor.

It was a warm welcome that contrasted sharply with last week's treatment, when Burris showed up on Capitol Hill to be sworn in with his colleagues, only to be turned away by Reid and Durbin, the No. 2 Democrat in the Senate. They argued that Burris' appointment wasn't valid under Senate rules.

But as the scandal-scarred Blagojevich watched, Burris dug in and the two Senate Democratic leaders ultimately relented under pressure from Obama and rank-and-file Democrats who worried that the episode was distracting from more important matters and putting the party — and the president-elect — in a bad light.