Tennessee senator known as ‘the great conciliator’

Howard H Baker Jr, a soft-spoken Tennessee lawyer who has died aged 88, served three terms in the Senate, was the chamber's Republican leader and earned a reputation as "the great conciliator".

Baker found his greatest fame in the summer of 1973, when he was the ranking Republican on the special Senate committee that investigated the wrongdoing of the Nixon White House in the Watergate affair. In televised hearings that riveted the nation, he repeatedly asked the question on the minds of millions of Americans: "What did the president know, and when did he know it?"

Baker described his political philosophy as “moderate to moderate conservative”. Friendly and unfailingly courteous, he was popular with legislators of both parties, a political type much scarcer on Capitol Hill today.

Schooled in the art of compromise by his father-in-law, Senator Everett Dirksen, Baker was heir to a centrist Republican tradition and then its standard-bearer.

When the Watergate affair thrust him into the national limelight, he exhibited a willingness to look hard at the actions of a president from his own party. Baker was also ambassador to Japan for four years and White House chief of staff for one. He made two tries for the presidency, but will be remembered as, quintessentially, a man of the Senate. He served there from January 1967 to January 1985. He was the minority leader from 1977 to 1981, then majority leader after his party took over the Senate in 1980.

Champion debater

He was born in 1925 in Huntsville, a Republican-leaning region of Tennessee. His grandfather was a judge, and his grandmother the first woman to serve as sheriff in the state. A champion debater at school, he attended a military academy and served briefly in the navy during the second World War. He ran unsuccessfully for the Senate in 1964 and successfully in 1966 winning support from some traditionally Democratic sections of the electorate.

Baker's performance on the Watergate committee made him a figure of national prominence, his calm, lawyerly manner complementing the folksiness of the committee chairman, Sam Ervin. In 1980, he made a brief run for the presidency, finishing third in the New Hampshire primary, behind Reagan and George Bush.

When it became clear that Reagan would win the nomination, Baker let it be known that he would like to be the vice-presidential candidate. But Republican conservatives blocked him. The same qualities that had made him such an effective legislator – the willingness to break with party ideology and work with the opposition – made him unpopular with the party’s ascendant right wing.

He retired from the Senate in 1984 and joined the law firm of Vinson & Elkins, where he reportedly earned close to $1 million a year. He was ambassador to Japan for four years beginning in early 2001. In 2005, he became an adviser to Citigroup on international issues. In 2007, he and three other former Senate leaders, Bob Dole, George Mitchell and Tom Daschle, founded the think tank the Bipartisan Policy Center.

His first wife, Joy Dirksen, died in 1993. He is survived by his second wife, Senator Nancy Kasselbaum.