But Mr Bush, who continues to insist he will not "play the Washington game" of personalised politics, also attracted defenders, with one of his rivals for the nomination, Senator John McCain, saying he was entitled to his privacy and Ronald Reagan's speech writer, Peggy Noonan, using The Wall Street Journal to advise him to "Stonewall, Mr Bush".
In Ohio yesterday, Mr Bush did just that. He insisted he was trying "to purge the system of ugly politics" and advised parents of his own "baby- boom" generation to tell their children: "I've learnt from mistakes I may or may not have made and I'd like to share some wisdom with you and that is - don't use drugs."
An opinion poll released yesterday showed an overwhelming majority - 84 per cent - of those asked saying that past use of hard drugs, including cocaine, should not be a bar to presidential office.
That office's current incumbent, Bill Clinton, is remaining aloof from revived allegations about his own drug use. In a television interview on Wednesday night, one of the women with whom Mr Clinton has been associated, Gennifer Flowers, repeated an old claim that he took cocaine while he was attorney-general of Arkansas. In his first White House campaign Mr Clinton rebuffed drug-taking allegations, admitting only to smoking marijuana while at Oxford - without inhaling.