Mr Clinton, facing further charges that he received special treatment in his efforts to avoid service in Vietnam while studying at Oxford, is urging fresh examination of the arms-for-hostages deal with Iran in 1985 and the role of Mr Bush, then vice-president to Ronald Reagan.
Attention is being directed to a newly uncovered memorandum between former Reagan cabinet members Caspar Weinberger and George Shultz, voicing indignation over claims made by Mr Bush in a 1987 newspaper interview that he was 'out of the loop' on White House discussions about the secret deal.
Irritated by the continuing investigation of his draft record, Mr Clinton has challenged journalists to redirect their energies to the potentially incriminating note. 'There is a memorandum about a conversation between two cabinet members, which, if true, would call into question not only the President's veracity but his support for illegal conduct,' Mr Clinton said.
The Democrat leader of the Senate, George Mitchell, called yesterday for a renewed investigation into President Bush's precise role in the Iran-Contra affair, which also involved skimming off profits to support Contra rebels in Nicaragua.
The memo, Mr Mitchell declared, raised new questions 'about the completeness and the accuracy of the President's prior response on the subject', adding that an attempt should be made to persuade Mr Weinberger and Mr Shultz to clarify their positions.
The memo was recently introduced in court by prosecutors who, in July, formally laid charges against Mr Weinberger, the former defense secretary, in connection with the scandal. It records Mr Weinberger expressing to Mr Shultz, then secretary of state, his outrage that Mr Bush should have denied knowledge of the deal. The statement was 'terrible', he said. 'He was on the other side. It's on the record. Why did he say that?'
The discovery of the memo seems to represent a serious threat to Mr Bush and his claim to be the candidate voters can trust. For the time being, however, the issue is being overshadowed by a curious contest between the candidates to claim the mantle of the former president Harry Truman.
In their Labor Day speeches, President Bush and Mr Clinton, evoked the Truman name no fewer than 20 and 22 times respectively, with both pouring scorn on the other's efforts to lay claim to the Truman inheritance. Which of the two is winning the argument is hard to discern. How much voters care is also unclear.
Any hope Mr Clinton may have had of disposing of the draft issue in the final weeks of the campaign seem to have been buried by further revelations last week that an uncle pulled strings to find him a place in the Naval Reserve to duck going to Vietnam. Mr Clinton had made no previous mention of the offer, which he did not take up.
Reminders of the potency of the issue are appearing at virtually every public appearance now being made by Mr Clinton. At a Labor Day picnic in Cincinnati on Monday, an aircraft circled above Democratic supporters trailing a banner with the message, 'Draft Dodger'. Similar plane-trailed banners have been appearing at other rallies.