WASHINGTON — With a traveling salesman's enthusiasm, President Bush has been trying to convince the American people that Social Security must be reformed if it is to survive for future generations.

But when that highly partisan debate shifts to the U.S. Senate later this year, there will be a new face pitching the reforms — that of Sen. Bob Bennett, R-Utah.

For years, Bennett has been recognized in the Senate as an expert on Social Security reforms. He not only campaigned on the issue during his first race in 1992, but he has being studying it ever since, holding hearings through the Joint Economic Committee, of which he is the co-chairman, and pitching his findings to colleagues on both sides of the aisle.

And people are listening to his ideas.

"The reaction so far among the Democrats is 'Let's talk.' No one has said I'm crazy, that this is a non-starter," said Bennett, who has already met with administration officials who have expressed a willingness to listen to his plan.

Bennett's plan is two-pronged. First, the benefits paid to retirees would be indexed according to income. Those who rely exclusively on Social Security for their retirement income would get the lion's share of the benefits; those with higher incomes would receive fewer benefits.

"That would take care of a very large portion of the shortfall," Bennett said. "It is fiscally sound and there is precedence for it."

The second part of the package would be a private savings program similar to that proposed by Bush. But Bennett's plan would initially allow people to voluntarily contribute to the plan and to only make contributions above the amount they are now paying in Social Security taxes.

After five years, participants could then decide if the investment was worth it and only then shift a portion of their Social Security taxes into a personal retirement account.

"It would not be mandatory, nor would it be immediate," Bennett said.

"Put those two (indexing for income and private accounts) together and we solve the majority of the problem and maybe all of it," he added.

Officially, the legislation will come out of the Senate Finance Committee, and since Bennett is not a member of that committee he has no official standing on the issue. Unofficially, Bennett is recognized as an expert by both sides of the aisle, and Finance Committee Chairman Chuck Grassley, R-Iowa, has asked Bennett to work with him on crafting legislation.

Competing bills could come from Sen. Lindsay Graham, R-S.C., who likes Bennett's plan and indicated he may incorporate it into his own, and from Sen. John Sununu, R-N.H., who has been peddling his own ideas to Republicans.