In an op-ed piece in Sunday's New York Times, Mr. Clinton said he pardoned Rich, who allegedly evaded $48 million in U.S. taxes, and his partner Pincus Green for a number of reasons - and only after concluding that the case should have been handled in a civil rather than criminal court.
"The suggestion that I granted the pardons because Mr. Rich's former wife, Denise, made political contributions and contributed to the Clinton library foundation is utterly false," the former president wrote.
Mr. Clinton's pardon of Rich, who has lived in Switzerland since fleeing a 1983 indictment on tax evasion and other charges, has prompted an investigation by federal prosecutors in New York and congressional hearings in Washington.
Investigators want to know if Rich bought his pardon by passing money through his ex-wife, Manhattan socialite and Democratic fund-raiser Denise Rich, who has acknowledged making large contributions both to Hillary Rodham Clinton's Senate race and to the Mr. Clinton's presidential library. Democratic Party sources have put the library donation at $450,000.
In his op-ed piece, the former president cited eight reasons for his decision, five of which he said were directly related to his conclusion that the case was improperly handled when criminal charges were first filed.
Another reason, Mr. Clinton wrote, was that "many present and former high-ranking Israeli officials of both major political parties and leaders of Jewish communities in America and Europe urged the pardon of Mr. Rich because of his contributions and services to Israeli charitable causes."
But New York City Mayor Rudy Giuliani, who as a U.S. attorney brought the federal prosecution of Rich and Green in the 80's, said Sunday that Mr. Clinton's reasons for the pardons seem to have shifted.
"Now you have the president saying that he determined the indictment was wrongful. This is a very strange use of pardon power." Giuliani told CBS News' Face The Nation. "You might remember the first time the president was asked about this on January 22, he said they had paid their price in full. Now we have a different explanation."
Giuliani called it "kind of an amazing thing" that Rich ran away from a "wrongful indictment" for more than a decade and a half, spending $100 million in legal fees and renouncing his American citizenship along the way, rather than face trial.
Elsewhere in the op-ed piece, Mr. Clinton said he specifically fashioned the pardon to allow for the pursuit of possible civil charges against Rich.
"There was absolutely no quid pro quo. Indeed, other friends and financial supporters sought pardons in cases, which, after careful consideration based on the information available to me, I determined I could not rant," he wrote.
Mr. Clinton noted that under the terms of the pardon, Rich was required to waive all legal defenses he might have planned to use in the event of civil litigation brought by the government after the pardon.
Furthermore, the ex-president wrote that "the case for the pardons was reviewed and advocated" by former White House counsel Jack Quinn and three Republican attorneys: Lewis Libby, Vice President Dick Cheney's chief of staff; Leonard Garment, a former Nixon White House official; and William Bradford Reynolds, a former official in the Reagan Justice Department.
However, the three lawyers say otherwise.
Garment told CBS News Chief Washington Correspondent Bob Schieffer about Mr. Clinton's citing him in the op-ed: "I have had nothing to do with Rich for seven years.''
Reynolds, who had represented Rich at one point in the past decade, told Face The Nation's Gloria Borger that he never reviewed, nor advocated, the pardon for Rich - and he said when he heard of it, he was as astonished as everyone else was.
And, White House spokesman Ari Fleischer said Libby was involved in Rich's original case but "was in no way, shape, manner or form involved in the pardon."
Noting the Republican lawyers' denials, Giuliani on Face said Mr. Clinton's latest explanation could only complicate the various investigations of the Rich and Green pardons.
"Every time the people defending President Clinton, including the former president, explain it, including the article today, they raise more serious questions than existed before, the mayor said.
Rep. Dan Burton, the Indiana Republican who chairs the House panel that's been looking into the Rich and Green pardons, vowed on Face The Nation to send a rebuttal of Mr. Clinton's op-ed to the Times.
For example, Burton noted the former president's reference in his piece to two academics who sided with the fugitive financier in their analysis of the case.
"The two professors that wrote the piece that indicated that Marc Rich didn't do anything wrong - well, his attorney, Marc Rich's attorney, paid those two people $100,000, which had to come directly from Marc Rich, to write that," Burton said. "So, it was a very biased piece. Obviously it was going to favor his position on the tax evasion issue."
But whether Burton will call Mr. Clinton to testify before Congress about the pardons is another matter.
"I have said from the beginning that unless we find some reason to believe that there may have been a quid pro quo or he did something wrong, I don't think we need to have him before the committee," he said.
California Rep. Henry Waxman, the ranking Democrat on the House Government Reform Committee chaired by Burton, said an in-person defense of the pardons by Mr. Clinton on Capitol Hill is up to the former president.
"He'll have to decide that for imself whether he should be testifying before the U.S. attorney in New York, before the Senate, before the House. In fact, that points out the fact that we've got three redundant investigations going on at the same time," Waxman told Face The Nation.
"This matter warrants an investigation. And now that the law enforcement has taken over to investigate whether there was wrongdoing, I think that they're the ones that we ought to defer to," Waxman added.
In concluding his op-ed piece, Clinton said he was used to the "rough and tumble of politics, but the accusations made against me in this case have been particularly painful because for eight years I worked hard to make good decisions for the American people."
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