This year's Republican tilt toward bread-and-butter politics peaked last week when Jeffrey Bell, running uphill for the Senate against heavily favored Democrat Bill Bradley, pulled a dollar bill out of his pocket while addressing Kemper Insurance employees.

"This is the only thing we ask the government to produce, to keep it at one dollar a year from now - not 89 cents, not 92 cents," said Bell. But "we can't trust them anymore" to do that. President Richard M. Nixon broke the cord between gold and the dollar in 1971, he said, "taking advice from the professors at Harvard and MIT."

It is political audacity to confront an unprepared audience of office workers with arcane talk about Nixon closing the gold window - and particularly so in view of Bell's massive problems. Still unknown despite his spectacular upset of liberal Sen. Clifford Case in the Republican primary, 34-year-old conservative activist Bell not only faces the huge Democratic majority in New Jersey, but also, in ex-basketball hero Bradley, he confronts a first-time candidate with phenomenal name recognition.

Bell's abstruse discussion of currency standards fits his depersonalized strategy: Ride the anti-government tax revolt. Bradley, though a political rookie, follows the familiar Democratic formula of personal appeal and promises of more and better government service. In terms transcending Bradley and Bell, the New Jersey Senate race is what politics 1980 is all about.

Although Bell was a 1976 presidential campaign aide to Ronald Reagan, he says his ideal in politics is New York's Rep. Jack Kemp. He trumpets the Kemp-Roth tax-reduction bill as the economic cure-all with a monomania approaching Kemp's own. "We are strangling the American economy with high taxes," Bell tells audiences.

The lecture on the gold-less, shrinking dollar was Bell's response to Bradley's attack on Kemp-Roth as inflationary. Holding out the dollar bill was a gimmick from the inventive mind of author-journalist Jude Wanniski, an adviser to both Kemp and Bell. Taking his advice, Bell turns his speeches into economic seminars even more than Kemp does.

"The working man may not read books of economics, but he does read his own paycheck," Bell told a luncheon of employers in Elizabeth. "He is ready to be talked to." But Bell, looking a bit like Wall Street in a three-piece suit while local Republican politicians wearing white shoes trotted after him, seemed less comfortable after lunch touring the courthouse.

In contrast, the shirt-sleeved Bradley is a natural, low-key handshaker who signs more authographs in five minutes than Bell does in a week. Basketball, not politics, is the link. "I only hope you make a good senator like you were a New York Knicks basketball player," one woman gushed to him at a nursing-home stop.

The prototype liberal campaign waged by Bradley in the Democratic primary has been blurred in deference to Bell's tax-cut crusade. But Bradley still gives a good working definition of liberalism when he tell audiences his intent is "to help people and create a better life for people." Opposing Kemp-Roth, Bradley advocates some tax reduction and even unspecified budget cuts. He called "dollar bill" Bradley as a Knick "because I saved my pennies. Now I'm going to save yours."

Bradley's bromides surely would carry him to the Senate at age 35 (I'm pretty old for a basketball player but pretty young for senator," he modestly tells audiences), save for two possible factors.

The first is the heavy advantage of Bell - intense and articulate - over the mellow Bradley in the battle of words. A 6-foot-3 non-athlete, Bell says he will go one-on one with Bradley in basketball in return for a weekly debate. Even Democratic politicians believe Bell far outshot Bradley in their first two debates.

The second is the possibility that Bradley might be out of step on the issues. As he was leaving the Ocean County fair in Lakewood, Bradley was confronted by a woman who told him she thought Bell was "a real go-getter" but that she was voting for Bradley "because I've followed your career for all these years - you know, with the Knicks." Then, as an afterthought, she asked about capital punishment. When Bradley expressed opposition, her face fell but she quickly added, "Oh well, nobody's perfect."

Bell's chances may depend on whether he can convince Jerseyites that Bill Bradley is really not that good guy they watched on TV so many years as the archetypal team player but a big-government liberal not in step with public opinion on capital punishment or anything else. But to do that will require far more than lecturing white collar workers on the gold-dollar relationship while his opponent shakes hands across the state.