BURLINGTON, VT. -- This morning Rep. Peter Smith, a freshman Republican, will introduce President Bush to a breakfast of GOP contributors here. To say that he anticipates the moment with mixed feelings is to understate the case.

Smith is plainly in need of help as he seeks to defend two unpopular votes for budget packages that have been criticized by his well-known opponent and to clarify for Vermont voters the principles that lie behind his tortuous decisions on the fiscal dilemma.

Most of all, he needs to explain why he and the president are standing there, raising campaign dollars, while the budget is still in limbo, held hostage to a partisan fight in Washington.

When he visited his statewide district over the weekend, Smith said yesterday, constituents told him "they were not so much upset about specific parts of the budget as the fact that Congress doesn't seem to be able to do anything. They kept asking, 'When are you guys going to do what you're supposed to be doing?' "

The former college president, 44, is hardly the typical incumbent. He was the first rank-and-file member in either party to endorse the Sept. 30 budget summit agreement, which quickly crashed in flames, and one of only 10 Republicans to support its Democratic-designed successor. He is also one of the few House members with an opponent who has matched him in fund-raising and made his own views well-known.

The political torment Smith has suffered these last few weeks speaks volumes about the difficulty of being a vulnerable incumbent when the long-delayed bills fall due.

Back in 1981 when President Ronald Reagan persuaded Congress to embark on the fiscal policy experiment that then-Senate Majority Leader Howard H. Baker Jr. (R-Tenn.), called "a riverboat gamble," Smith was a freshman Vermont state senator working on his doctorate in education at Harvard. Though he had no part in the decisions that led to the record-breaking deficits, he said in a recent interview, "I knew we couldn't put off dealing with it any longer."

His rush to embrace the summit agreement was viewed by many in Vermont simply as a political bill due to Bush, who was scheduled to speak at a fund-raiser for Smith on Oct. 5 -- five days after the deal was cut. The event was postponed until today by the budget crisis. "Peter desperately needed fund-raising help," said University of Vermont political scientist Garrison Nelson, "so he faxed in his support of the first budget, even though it included a fuel-oil tax and big cuts in Medicare."

That is grist for the mill of Smith's main challenger, independent Bernie Sanders, the socialist former mayor of Burlington who came within 8,900 votes of beating him in 1988 and was tied with him in the polls even before the budget issue came along. Sanders has campaigned for years on the claim that Washington politicians rip off working people to protect the special interests.

With no viable Democrat in the race this year, the budget battle gives Sanders a clear-cut test for his anti-wealth appeal. As editor Emerson Lynn wrote in the St. Albans Messenger, "The political scenario is beyond Sanders' wildest dreams. . . . If he can't win with this help, he can't win in Vermont."

Why then did Smith do it? In an interview in his office a few days after the first budget failed, he said, "From the beginning, I've viewed this as the first real opportunity in many years to fix a {deficit} problem that will inevitably cause us grievous economic damage. I determined that if I saw a package that was fair and enforceable, I would support it -- even if I didn't like everything in it."

That stance won him considerable support on editorial pages at home, but when the summit agreement collapsed -- with majorities of both Republicans and Democrats opposing it -- Smith was left to defend the unpopular parts of the deal without being able to claim that his vote had helped solve the deficit problem.

At a White House meeting Bush held with a group of House Republicans after that first vote, Smith urged the president to "be flexible" on the terms of a new package but not to relent on his promise to shut the government down again if the new deadline of Oct. 19 were not met. Bush ignored the advice.

As Smith readily conceded, "I am not a power broker, so I have to take these packages as they come to me." The next package was the Democratic-designed bill, condemned outright by the White House because it boosted the tax rate on the highest-income earners to 33 percent, added a 10 percent surtax for millionaires and delayed indexing for everyone for a year.

Once again, Smith announced he would vote yes, thereby separating himself from the president and all but a few other House Republicans. His reward was scorn from his opponent and fresh criticism from others in the Vermont GOP.

"I think Mr. Smith was humiliated by the vote he cast that would have cut Medicare $60 billion, boosted the tax on gasoline and home heating oil," Sanders said. "Now he is trying to make amends." Sanders said he would have opposed even the Democratic plan because it still cut Medicare, and instead would have held out for slashing the Pentagon budget and imposing stiff taxes on the rich.

Tim Philbin, the conservative Republican who won 38 percent of the vote against Smith in the September primary, said, "It seemed that after taking a lot of criticism, he swung to the Democratic position -- at least that's the way it looked to a lot of people."

Smith was not passive in the face of the criticism. He stayed late in the office the night the House passed the new package, phoning his comments to the Associated Press and the two largest morning papers in his state. As a result, his "spin" -- emphasizing that the gas and heating oil taxes were gone and that Medicare received better treatment -- was included in the first stories. He repeated the same points in radio interviews the next day, while his campaign started airing a new ad with the tag line, "Doing what's right isn't always easy. But it's always right."

Then, while conferees wrestled with a new version of the budget, Smith headed home. On Friday, he toured a series of elderly housing high-rises, trying to calm some badly rattled senior citizens. "Social Security and the COLAs {cost-of-living adjustments} have been protected," he said. "No matter what you've heard elsewhere, spending for Medicare will go up no less than 50 percent in the next five years. That's the good news. The bad news is that medical costs may go up even more, so your bill goes up too. No one is going to get off scot-free."

The seniors were skeptical, but Smith did get some nods of agreement when he accused Sanders of taking the easy way out. "You can't be against everything," Smith said. "I'm surrounded down there by politicians who duck their responsibilities and postpone decisions. I'm not going to play that game."

Emerson Lynn and other editorialists picked up that same point to criticize Sanders, and many prominent Democrats, including Winooski Mayor Ronald P. "Pete" Lacourse, who accompanied him on part of the senior citizens tour, have endorsed Smith. But Smith's argument that Sanders offers only empty protest gestures while Smith himself plays a responsible and constructive part in the process has been grievously undercut by the continuing budget impasse.

"Obviously, the circumstances {of the Bush visit} give me a problem," Smith acknowledged yesterday. "Every day we don't deal with this is further proof Congress is in gridlock and is not serving the people well."

Many of his constituents require no further evidence. Interviews at a shopping mall here found general contempt for Congress washing over onto Smith. "I don't know who's to blame," said Judy Waters, a cook, "but I know what they're talking about is not good for the working people . . . and Bernie Sanders is against it."

Smith, who has heard many such comments, said yesterday, "I know people feel very alienated, but there is no antidote other than doing the job. I've been telling myself that now for three weeks, since the first budget came to the floor. I hope I'm not kidding myself."