With a decisive margin in the Senate, Republicans, who have shown their willingness to accommodate the president-elect, will have the numbers to overcome divisions over his personnel and policies.
After picking up seats in West Virginia, Ohio and Montana and winning an unexpectedly close race in Nebraska, the G.O.P. sealed a majority. Tight races in swing states will determine their margin.
He became ambassador after three terms as a senator from Tennessee. In 1999, he was made a virtual prisoner in the embassy in Beijing during a siege by protesters.