Exactly one year after Mr Clinton was forced to admit that he had indeed had a relationship with Monica Lewinsky, a suddenly defensive George W found himself pursued by reporters interested in only one thing: had he ever used cocaine? The directness of the question, and the reporters' persistence, caught the early favourite for the Republican nomination with his guard down.
Twice elected Governor of Texas without having to answer the "C" question, he was spared it again this spring, when he took off into the wide world of national politics to near universal acclaim. When he launched his presidential campaign in earnest, he marked his private life off-limits.
In this, he was ably supported by his fiercely loyal team of advisers. His campaign machine is more cohesive and professional than that of any other candidate. Yet when the "C" question was finally raised last week, his response was described by American campaign-watchers as "about as bad as it could be".
His first error, said Paul Gigot of the Wall Street Journal, among others, was his decision to expose some aspects of his private life and not others. He boasted, for instance, of his fidelity to his wife. He acknowledged a drink problem in his thirties, which he solved by renouncing alcohol at 40. But he banished other aspects, speaking of "mistakes" which should be consigned to the past.
Last week, the US media finally seized on the inconsistency and said, in effect, that he could not have it both ways. In one sense, said Gigot, "it's refreshing to see a politician try to draw a line on personal privacy. But then he has to be consistent about all private matters".
Having established this dual strategy, Mr Bush's second mistake - identified by Tom Oliphant of the Boston Globe - was to have deviated from it even by a fraction. "At the first sign of heat," he said, "he wilts." After trying to hold the line, Mr Bush selected one question put by his local paper, the Dallas Morning News. Would he, as President, continue the practice of background checks for White House employees, and would he pass? "Yes", and "yes", Mr Bush replied - putting on the record that he had not used drugs for at least seven years.
The next morning, Thursday, clearly perturbed by the impression this might create (only seven years?), Mr Bush issued a statement - his first on the subject - saying that he would have passed the White House background check also "when my dad was President" (from 1989 to 1993), when the required drug-free period was 15 years. Mr Bush left it to his office to clarify that the 15 years should be counted back from his father's first year in office, taking George W Bush's drug-free period back to 1974, when he was 28. As Oliphant put it: "This was not just a flip-flop, but a flip- flop on a flip-flop."
By Friday, Mr Bush was again trying to hold the line. Asked what parents should be telling their children about drugs, he said they should use the benefit of their experience to say: "Don't use drugs. Don't use alcohol." Drawing the public/private line again, however, he refused to say what he had told his own two daughters.
By yesterday, few US political observers believed he would be allowed to leave the cocaine question there, even though no one has any proof that he took it. But any admission will only prompt more questions: such as when, where, how and how much, and whether he brushed with the law. Several US media watchers said that he should have come clean much earlier.
Unfortunately for Mr Bush, the question has now shifted from the fact, or not, of an aspiring President's use of illegal drugs towards the way in which he has dealt with the allegations. "I've told the American people all I'm gonna tell them," Mr Bush told reporters on Friday, prompting one analyst to remark: "He has violated just about every law of mature campaign behaviour."
To British eyes, it might seem remarkable that Mr Bush is only now having to face questioning. This tardiness matches the US media's non-reporting of an affair between the Republican Speaker of the House of Representatives, Newt Gingrich, and a young Congressional aide at the very time of Mr Clinton's liaison with Ms Lewinsky. The affair has made its way into print only now that he is out of office and seeking a divorce.
The mainstream US media fight shy of reporting such matters without prima facie proof. They also say that in fact Mr Bush is being targeted early in the election campaign; this, they say, is because he already seems a more plausible candidate than most of his opponents.
Some see jealous rivals behind the offensive. Others suspect Democrats, prompted by the Senate minority leader, Tom Daschle, who compared what he saw as the easy ride the media were giving Mr Bush with the criticism of Hillary Clinton. A newspaper then asked each candidate if they had ever used marijuana and cocaine. Mr Bush was the only one not to answer the cocaine question. All the others answered "No".
This time last week, Mr Bush won the "straw poll" in Iowa. Seven days later, he looks vulnerable for the first time. If a week is a long time in politics, then the year between now and the nominating convention next August, and the following election, is much, much longer.