Wisconsin's offbeat race for US Senate pits grocer against housewife. K"UCHEN WARS

WELCOME to the supermarket Senate race where the coffeecake gap has replaced the missile gap as an issue of national import. Today's election special is Democrat William Proxmire's United States Senate seat.

The pinchpenny Senator Proxmire retires as the fourth Wisconsin luminary to hold the seat since 1906. His predecessors, all bellwethers of their political eras, were Robert M. La Follette, Robert M. La Follette Jr., and Joseph R. McCarthy.

Campaigning hard for that venerable post are supermarket namesake Herbert Kohl - running as if he were an incumbent though he has never held office - and Susan Engeleiter - perhaps the first US Senate candidate in history to attack her opponent with a coffeecake.

But first, let's see if you can identify which candidate is from which party.

Mr. Kohl is a successful businessman who is bankrolling his expensive campaign with his own fortune.

Mrs. Engeleiter is a 13-year veteran of the Wisconsin Legislature who is receiving money from special-interest groups to help keep up.

``I tend to go Republican and I'm thinking Herb Kohl right now,'' says Mark Nowaki, a clerk at a Madison savings-and-loan.

Bruce Douglas, a University of Wisconsin medical school student, says he tends to vote Democratic. ``Kohl frightens me a bit, because of the money, the business background.''

In fact, Kohl is the Democrat, who says he's so rich that he won't kowtow to special interests.

Engeleiter is the Republican, who talks liberal on environmental and social issues.

As for the supermarket strategy, Kohl's name is printed on thousands of bags picked up by Wisconsin food shoppers each day. A former owner of the popular Kohl's supermarket chain, Kohl now owns the Milwaukee Bucks and is following a ``Rose Garden'' strategy based on his high profile in the private sector.

In a recently televised debate, Engeleiter even waved a coffeecake from Kohl's in an attempt to get his attention.

The coffeecake cost her $2.59, but she said that despite Kohl's criticisms of special interests and defense contracts, his bakery sold coffeecakes to the US Defense Department for $7.52 each.

Kohl's campaign flew coffeecakes to Milwaukee from the Arizona bakery to rebut the charges.

A spokesman explained that the candidate had sold the bakery and that the coffeecakes in question were larger and designed to meet government specifications.

All of which says little about the candidates' stands on issues but a lot about the course of this campaign. Polls indicate Kohl has a good lead, but the race is still close.

``I'm not a politician, I'm a businessman,'' says Kohl, who plans to use the same principles that made his family's supermarket business successful to bring the federal government into line.

In his vision of government as supermarket, Congress should make ends meet, should foster cooperation between management and labor to make US business competitive, and should promote education, research, and plant modernization.

Such a vision attracts Wisconsin voters, who always have a soft spot for a maverick `a la ``Fighting Bob'' La Follette.

Even the retiring Mr. Proxmire, who was reportedly not happy with Kohl's loose spending habits in the Democratic primary, says he thinks the supermarket model is a good one.

``I shop in the [Kohl] stores a lot myself, because I'm too cheap to go into restaurants, and those grocery stores are just a dream,'' says Proxmire, whose idea of shopping excitement is probably collecting generic food labels.

Spending by both campaigns isn't out of line for a Senate race but pales by comparison with Proxmire's record.

He spent only $145.10 on his last race.

Millions and millions, as Carl Sagan might put it, are being spent so Kohl and Engeleiter can share ideas on holding down federal spending.

Kohl's main proposals are to cut defense spending by 10 percent and to raise taxes on the upper-income tax bracket.

Engeleiter, by contrast, says she wants an inflation-adjusted freeze on federal spending, similar to one she says she helped pass in Wisconsin. She also favors a reduction in capital-gains taxes.

Kohl wants a national health insurance plan; Engeleiter emphasizes the need for health programs at the state level.

A main difference in their foreign policy views, besides that of defense spending, is that Engeleiter says she would have favored escrowed military aid to the contras in Central America.

Kohl, who earned political experience as a former state Democratic Party chairman, has been relying heavily on TV ads and ducking some proposed joint appearances with Engeleiter.

He's left her to press her case alone at some forums with all the vigor of a woman who first won election to the Legislature by campaigning door to door at age 22, and is now Republican Senate leader there.

``It's a real role reversal, isn't it?'' Engeleiter likes to say. ``Middle-class lady with two kids running against millionaire businessman.'' Speaking of campaigning difficulties, she mentions problems of keeping up her children's attendance at Lutheran Sunday School.

``If this were old-fashioned campaign politics with no ads, she'd win hands down,'' says an Engeleiter campaign worker.

Yet Kohl has a certain awkward but appealing Frank Capra style on the campaign trail. He is often seen as the man who kept the Bucks in Milwaukee, and, more important, as a fair employer who listened to his workers while running Kohl's.

Such a reputation won him a relatively warm reception from glum workers at 5 a.m. recently outside the doomed Kenosha Chrysler plant.

``I just hope he can help your average John Q. Public,'' said worker Chuck Beckman. ``It's about time that someone stops what big business is doing to middle-class America.''

Focusing on their backgrounds, both expose themselves to arrows of critics.

While many ex-Kohl employees express support for their former boss, some shoppers in the union town of Kenosha said they don't because after his family interest was sold, a subsequent owner laid off workers and hired them back at lower salaries.

And while Engeleiter portrays herself as the candidate of the common people, she and her husband are in a high income bracket today, while her opponent came from a modest Jewish immigrant home.

Each candidate says the other is hiding something of their identity from the public. He says her voting record in the Legislature was more conservative than her US Senate-election rhetoric; she says he hasn't divulged as much about his property holdings as he should.

Their campaign slogans are mirror tributes to the Wisconsin heritage they both seek to succeed: ``Experience money can't buy'' is one of Engeleiter's mottoes, while Kohl says he will be ``nobody's senator but yours.''