Republican or Democrat, members of Congress generally agree that large campaign contributions have an undue influence on political decisions. That’s why a bill that would eliminate the public financing system for presidential campaigns makes so little sense.

The proposal by Sen. Pete Domenici, who is chairman of the Senate Budget Committee, would abolish a system that has been used by all but one presidential candidate since 1974. Sen. Domenici is calling for an end to public financing, which he says will reduce the budget. But the small amount of tax money saved from campaigns would be overwhelmed by the loss of control of the election system to special interests.

The measure is even more cynical than that. Public financing would remain through 1996 under this bill — long enough for a GOP challenger such as Sen. Phil Gramm or Sen. Bob Dole to receive the public money — then would be denied to any future candidates. The bill runs counter to measures designed to build faith in the political system.

An organization called the Center for Responsive Politics recently issued a book of interviews with 25 former members of Congress, who would be more willing to speak freely about the system than current members. Sen. George Mitchell was among those interviewed. The former Senate majority leader was direct on the influence of money in congressional decision-making: “I think it is clear that large contributors do get a disproportionate access to members of Congress,” he said, “and are at least able to present their case more personally and aggressively and effectively than others.”

Though there remains plenty to be cleaned up in the presidential races, the public contributions have improved the chances for challengers and reduced the impact of large private donors. The public money comes from the $3 checkoff on tax forms, and has worked well.

Congress has rejected a half dozen sensible reforms for cleaning up its own campaign process. It has no business attacking the presidential system. The public should oppose this measure, and President Bill Clinton has an obligation to speak out against it.