But as the endgame looms in this tortuous legal battle to oust the president from office, that is exactly what they've got.

The Chief Justice of the Supreme Court, William Rehnquist, follows Special Prosecutor Kenneth Starr and House Judiciary Chairman Henry Hyde at the helm of this historic episode.

Kenneth Starr's allegations are now in the hands of the Senate

If and when the Senate begins a trial of Mr Clinton, it is Mr Rehnquist who will take charge of proceedings.

He is certainly up to the task - his book, Grand Inquests, is a thorough study of two historical impeachment trials.

But at first glance the omens are not good for the Clinton camp.

Mr Rehnquist, 74, is a dyed-in-the-wool Republican. A Harvard-educated Lutheran, he came to prominence in the legal profession as a Goldwater Republican while practising in Arizona in the 1950s and '60s.

In 1969 he was appointed assistant attorney general in the Office of Legal Counsel, by the then-president Nixon.

Two years later, Nixon promoted him to the highest court in America and in 1986 President Ronald Reagan named him chief justice.

Mr Rehnquist has been called a "bugbear of liberals for four decades".

Richard Nixon: One-time associate of Rehnquist

In the 1950s he opposed school desegregation, backing instead "separate but equal" education for different races.

During the Nixon years he was a vigorous supporter of practices in the president's "law and order" programme, such as pre-trial detention, electronic surveillance and wire-tapping.

In 1973 he was a dissenting voice in the landmark case that legalised abortion.

He is known as a staunch opponent of affirmative action, gay rights and greater rights for criminal suspects, while backing the death penalty and greater ties between church and state.

Impeachment authority

But Mr Clinton's supporters will find succour in Mr Rehnquist's well-documented opinions on the impeachment process.

Since 1992, he has been a pre-eminent authority on the subject thanks to his book, Grand Inquests, which examines America's two most famous impeachment trials, including that of President Andrew Johnson in 1868.

In the book, Mr Rehnquist praises key senators in Johnson's trial for treating the case not as a political issue but a "judicial proceeding" dealing with violations of law.

Senators hold real power

House Republicans have been accused of following a strictly political agenda in the fight to oust Mr Clinton.

Commenting on the "precedent" set by the two historical cases, he says: "It was not any technical violation of the law that would suffice [for impeachment], but it was the sort of violation of the law that would in itself justify removal from office."