Howard Baker, a former United States Senate majority leader and presidential contender known for his ability to achieve compromise across the political aisle, has died at the age of 88.
Baker became the first Republican leader of the Senate in 26 years when he took the reins in 1981. He later went on to serve as chief of staff for president Ronald Reagan, to whom he lost the Republican nomination in 1980.
Current Republican Senate leader Mitch McConnell, who took to the Senate floor to announce Baker's death, hailed him as "one of the Senate's most towering figures".
He earned the nickname "the Great Conciliator" at a time when acrimonious partisanship was just beginning in Washington.
That tone of co-operation may have been his undoing on the White House campaign trail, as his party shifted rightwards and embraced Reagan, who called for a return to rigid conservative orthodoxy.
But President Barack Obama took note of the Tennessee senator's civility and bridge-building.
"It was his ability to broker compromise and his unofficial role as the 'Great Conciliator' that won him admirers across party lines, over multiple generations, and beyond the state he called home," Obama said.
Years after retiring from the Senate, Baker served as president George W. Bush's ambassador in Tokyo. Baker arrived just as Japan's often turbulent politics were stabilising under prime minister Junichiro Koizumi, who forged a close bond with Bush and took the landmark decision to send troops on a reconstruction mission to Iraq - the first time Japan had sent forces to a conflict zone since the second world war.
"He was someone that could do everything," Senate Democratic leader Harry Reid said. "He was well-liked by Democrats and Republicans."
The government in Tokyo paid tribute to a man it said "profoundly understood Japan".
"It is extremely sad to learn of the passing of former ambassador Baker, who profoundly understood Japan and played an active role in the friendship between Japan and the United States," said Yoshihide Suga, chief cabinet secretary and most senior government spokesman.
Early in his career, as the top Republican on the Senate committee probing the Watergate scandal, it was Baker who famously posed the central question of the investigation when he asked: "What did the president know and when did he know it?"