Second term presidents of the United States are vulnerable to scandals arising from the use and abuse of power, as with Richard Nixon and Watergate, Ronald Reagan and Iran-Contra or Bill Clinton and Monica Lewinsky. Often the political dynamic is created as much by the cover-up as by the original misdemeanour
This week George Bush has edged closer to such a fate with the disclosure that Karl Rove, his closest political adviser, spoke to a journalist about the covert CIA operative Valerie Plame in July 2003. Her husband James Wilson had just publicised his secret June 2002 report which said there was no basis for the administration's claim that Saddam Hussein was trying to buy uranium from Niger as part of a programme to develop weapons of mass destruction. Mr Bush repeated the claim in his 2003 State of the Union address. The White House ran a highly co-ordinated campaign to discredit Mr Wilson as a diversionary manoeuvre. In doing so it steered close to illegality, since it is a crime knowingly to disclose that a person is a covert agent. Besides which Mr Bush said he would sack anyone found to be responsible and his spokesman repeatedly denied Mr Rove was involved.
The affair deepened after a federal grand jury investigating the leak demanded that journalists reveal their sources. Time magazine decided to comply with the court order but the New York Times refused to do so following which its reporter Judith Miller was jailed. Ironically she had not written the story for publication and was already notorious for publicising evidence from the administration that Iraq had indeed weapons of mass destruction before the war.
Thus this has become a media cause célèbre - justifiably so given the deep issues of principle involved for the public functions and ethics of journalism. This was seen vividly in the fury with which White House spokesman Scott McLennon was questioned on Monday after Newsweek published details of a memo from a Time journalist giving details of a conversation three days before the information about Ms Plame was revealed by a right-wing columnist in the Washington Post. The issue goes far beyond the US media, which uncritically accepted the case for war, to engage the public depending on them to hold political leaders to democratic accountability and which have now shifted clearly against the war.
Mr Rove is crucial to Mr Bush's team. He engineered his election victories and is a constant strategist of the president's political agenda at home and abroad. He works closely with other conservatives in the administration, notably vice-president Dick Cheney. Were he to be a casualty of this affair - as he deserves to be - it would be a major setback for Mr Bush, whose second term programme is already in substantial difficulties. Pension and welfare reform, budgetary and trade deficits and disenchantment with the war in Iraq have cut into his popularity and created a sense of drift. This scandal bids fair to run and run.