The 100 US senators took an oath "to do impartial justice" to President Clinton when his impeachment trial opened yesterday on Capitol Hill. But behind the scenes the Republicans and Democrats failed to agree on the calling of witnesses in the historic trial.
The Senate may vote today on opposing motions on how to proceed with the trial if the two parties cannot agree on a common position.
As President Clinton appeared at an education ceremony in the White House, his spokesman complained that the trial could turn out to be "manifestly unfair".
Mr Joe Lockhart told reporters: "We may be in a situation where we do move forward without clear rules of the road." That would be "a situation, an environment that is manifestly unfair to the President".
White House lawyers and Senate Democrats are trying to prevent the Republicans from calling witnesses such as Ms Monica Lewinsky, the former White House intern, and Ms Betty Currie, the President's private secretary.
The White House has warned that if the Republican demand for witnesses prevails, the trial will be prolonged. "If they insist on bringing witnesses it will significantly extend and delay this process and all bets are off," Mr Lockhart said. "You're talking about a process that is open-ended and could go on for ever and ever."
This contrasted with assurances from Republicans on Capitol Hill that the trial could be wrapped up by mid-February even with witnesses. A CBS News poll yesterday showed that 63 per cent of Americans believe that a trial is not necessary.
A separate Gallup poll showed that 62 per cent say that the trial should last "just a few days". The President's approval rating in this poll has fallen 10 points to 63 per cent since last month.
It is the first trial of a US President since that of Andrew Johnson in 1868 and there was a suitably solemn air to the proceedings in the Senate chamber.
The day began with the 13 prosecutors, called "managers", from the House of Representatives walking across the Capitol building to the Senate to present the two articles of impeachment on which the President will be tried.
The senators were called to order with the traditional proclamation dating back 200 years. "Hear ye, hear ye, hear ye, all persons are commanded to keep silent on pain of imprisonment." The proceedings were presided over by the most senior member, 96-year-old Senator Strom Thurmond.
Several hours later, the senators re-assembled to be sworn in for the trial by the Chief Justice of the Surpreme Court, Judge William Rehnquist, who will preside. Earlier he had been summoned to attend and was escorted into the chamber by a "committee" of six senators, three Republican and three Democrat.
The chief justice wore his traditional black robe with four golden stripes on each sleeve. He got the idea of the stripes to distinguish him from the other judges from a performance of Gilbert and Sullivan's Iolanthe. But there was little else in yesterday's proceedings which could be called Gilbertian. There was a sobering realisation that the President of the most powerful country in the world was going on trial for alleged "high crimes and misdemeanours" and if convicted he would be ignominiously removed.
Meanwhile, eight prominent Protestant and Jewish leaders have written to each member of the Senate urging them to censure President Clinton and avoid "an exhausting, debilitating trial that could drive him from office".
The signatories representing mainstream Protestant churches and conservative and reform Judaism in the United States said the trial would "have deleterious international consequences" and divide the country.