According to Mr Blumenthal's testimony to the grand jury in the investigation by the special prosecutor, Kenneth Starr, he is in charge of the "special relationship", and looks after relations between Bill Clinton and Tony Blair. "He's an old friend of mine, I introduced him to the President and the First Lady, and I act as a personal liaison between the President and the Office of the Prime Minister," Mr Blumenthal told the investigators.
His statements about his role with Britain have not earned him many friends on either side of the Atlantic. There are plenty of other officials, like the ambassadors in London and Washington for instance, who think they handle that relationship, and regard Mr Blumenthal as a nuisance. Part of that may be plain envy: Mr Blumenthal, a former journalist who is exceptionally well-connected, does have genuine influence, though senior British officials have been warning Downing Street that those connections might be played down.
But it is not his London links which have put Mr Blumenthal in real trouble. The Starr inquiry wanted to talk to him about the media handling of the Lewinsky affair from within the White House, about information leaks from the inquiry itself and stories which had appeared about some of those conducting the probe.
Mr Blumenthal's testimony makes fascinating reading and shows his interrogators growing increasingly irritable about his way of giving testimony. He frequently cannot recall things, and asks for questions to be repeated, defined or reformulated. In his first session of testimony, he consults his lawyers 15 times in three hours, each time for an average of about five minutes.
The Starr investigators seem to believe that Mr Blumenthal helped leak evidence from the grand jury, and other information. Mr Blumenthal denies that he ever released any information illegally. The investigators seem to think there was a network of people gathering information for use against the President's enemies, centred on two daily meetings in the White House in which Mr Blumenthal participated.
Mr Blumenthal told the Starr inquiry that he had videotapes made of a television programme which concerned a row over the previous conduct of one of the officials on the Starr team. He gave one copy to the Democratic National Committee, so that they could give it to reporters. Mr Blumenthal also received information about the members of the Starr staff - before publication - from Stanley Sheinbaum, former commissioner of the Los Angeles Police Department. He passed on this information to someone, though their identity has been removed from the report.
The videos were copied by the consulting firm of Robert Shrum, a lobbyist; they were given to Doug Kelly, the "research director" at the DNC. Mr Blumenthal also received documents from the DNC which contained information about the officials on the Starr team, and he referred the media to people who would disseminate that information. There are references to private investigators who were working for Mr Clinton's lawyers.
Even some of Mr Blumenthal's friends say he is paranoid about the Right, and that he and First Lady - who spoke daily about the affair, according to his testimony - share a view that there is a vast conspiracy at work against the President.
Mr Blumenthal clearly sees himself as a defender of the President and the First Lady, and also of the truth itself. "I believe that the public has the right to know about the character and records of public officials," he said when questioned about releases of stories regarding the President's foes.Reuse content