The latest election year embarrassment for Mr Clinton blossomed at the weekend, with the revelation that in late 1993 his administration obtained FBI files on 341 people, many of them prominent Republicans - apparently as part of a review of individuals with entry passes to the White House. Although the exercise was halted after a few months, the files were only recently returned, after they were discovered in a White House vault.
The White House response has been to grovel, as Chief of Staff Leon Panetta apologised for what he termed an "inexcusable mistake" that was put right as soon as it came to light and the President talked of an "honest bureaucratic snafu" by a civilian Pentagon investigator on temporary secondment.
But in an election year, these excuses are unlikely to keep at bay a Republican Party for whom White House ethics and the "character" issue probably offer the best chance of victory this November for its future nominee Bob Dole. "It smells to high heaven," said Mr Dole, who has called for hearings into the affair.
How much mileage they can extract from it is unclear. Although the files are highly sensitive, containing background material running to 20 pages compiled by the FBI on people in public office, the White House appears to have progressed no further through the alphabetically ordered list than the letter G - including such luminaries as the former Secretary of State James Baker but hardly suggestive of a comprehensive search to discredit potential opponents.
And although few deeds by the White House raise more hackles among the press and rival politicians than misuse of the FBI, public opinion here may be no more impressed by the latest controversy than it has by three years of Whitewater and other allegations of skulduggery.
Polls, for instance, show that less than 20 per cent of Americans regard Whitewater as a "very important" matter. Sundry other Congressional probes may titillate the Washington cognoscenti, but they leave the general populace stone cold.
However, the fewer the chinks in Mr Clinton's policy armour, the more Republicans will turn to the ethics issue to fight their way back into a contest whose dynamics are illustrated by the President's current trip to California.
Once again Mr Clinton is stealing Republican clothes, stressing his concern over illegal immigration across the Mexican border, and boasting of the sharp decrease in serious crime, not only in Southern California but a host of large American cities.
And the policy is paying off. As Mr Dole signally fails to capture the country's imagination, the President continues to enjoy a 20-point lead in California, and is ahead in other western states he won in 1992, including Washington, Oregon, Colorado and New Mexico.