WASHINGTON — Members of the special House and Senate panels investigating the Iran- contra affair, who on Tuesday will open the most explosive set of congressional hearings since Watergate, expect their inquiry to further embarrass--but not destroy--the presidency of Ronald Reagan.
The House and Senate investigating committees, acting together to conduct the hearings, will begin questioning the first of as many as 50 witnesses in televised sessions that are certain to produce a wealth of new information about all aspects of the arms sales to Iran and the diversion of profits to the Nicaraguan rebels.
The hearings are expected to continue four days a week for at least three months.
Even if the committee succeeds in its efforts to avoid partisanship, Reagan's supporters acknowledge that it will be an extremely difficult period for the President as the panel picks though mounds of new evidence detailing how he undercut his own anti-terrorism policy by selling arms to Iran and how his enthusiasm for the contras was carried to improper--if not illegal--extremes.
'Very Little' Sides Can Do
"There is very little the Republicans can do to make the facts better than they are and frankly there is very little the Democrats can do to make them any worse than they are," admitted Sen. Warren B. Rudman (R-N.H.), vice chairman of the Senate committee.
"Inevitably," added Sen. George J. Mitchell (D-Me.), a committee member, "the revelations in the hearings will affect the President's public standing."
Comparisons with the Watergate investigation, which brought down the presidency of Richard M. Nixon in 1974, are inevitable. As with the historic Nixon inquiry in 1973, the Iran-contra proceedings will delve into issues that touch the heart of a President's conduct in office.
Further underlining the parallel, the hearings will open in the same Senate Caucus Room where the late Sen. Sam J. Ervin Jr. (D-N.C.) presided over the Watergate inquiry. The Senate panel this time will be chaired by a former Watergate committee member, Sen. Daniel K. Inouye (D-Hawaii).
As in the Watergate inquiry, the paramount questions at these hearings will be: "What did the President know and when did he know it?" Answers to these questions will be particularly critical in two broad areas:
--The apparently illegal diversion of Iranian arms sales profits to the anti-Sandinista rebels. Reagan has said repeatedly that he knew nothing about it, but opinion polls reveal widespread public skepticism over the President's account, and evidence already on the record makes it clear that some of his closest advisers were deeply involved in the diversion scheme.
--Reagan's role in the elaborate network set up to channel money and military aid to the contras from private donors and the governments of other countries at a time when Congress had prohibited direct U.S. military aid. At issue is the question of whether Reagan or others in the Administration went so far in their efforts to help the contras during this period that they engaged in improper or illegal conduct.
Evidence already amassed by the House and Senate investigating committees since they were created by Congress last January--including entries in Reagan's own handwritten diary--indicates that the President was intensely aware of the efforts of his aides to encourage private citizens and other countries to contribute to the contras from late 1984 to late 1986 at a time when direct U.S. military aid was prohibited.
Non-military, or "humanitarian," aid was not prohibited and foreign governments would not be subject to congressional restrictions. But it is not clear how all of the outside aid funds were used and legal and ethical questions have been raised about the extent of Administration involvement in thwarting the will of Congress.
New evidence on what Reagan knew about the diversion of Iranian arms profits is expected to come in the testimony of former National Security Adviser John M. Poindexter, who will appear before the committee in mid-June under a limited grant of immunity from prosecution. As Reagan's top foreign policy adviser beginning in December, 1985, he is the man most likely to know what the President knew.
"If Poindexter says the President knew what was going on," said Sen. Paul S. Trible Jr. (R-Va.), a committee member, "then we're in for some tough days."
Poindexter will be followed on the witness stand by his former deputy, Lt. Col. Oliver L. North, the energetic Marine who masterminded the contra supply network. One frequently quoted memorandum written by North while on the staff of the National Security Council states that the President "obviously knows" about the private fund-raising that was being carried out in his name.