RARE IS THE CONGRESSMAN who'll bring an overhead projector to a town meeting so he can lecture on the federal debt. And Wisconsin Republican Mark Neumann, to be sure, is no ordinary congressman. But his quirkiness -- along with an aggressive campaign and Bill Clinton's woes -- has put him in a dead heat in his campaign to unseat Democratic senator Russ Feingold.

Proof of Neumann's idiosyncratic bent is his choice of issues. He's hitting taxes and Social Security, which are conventional. He's also touching on partial-birth abortion -- a bit risky, but probably wise. Yet he's almost surely the only serious Senate candidate who's making his opponent's stance against a flag-burning amendment to the Constitution a top campaign theme. Also, Neumann says he won't be hanging the Clinton millstone around Feingold's neck.

Neumann has attracted attention recently with a hilarious TV ad, which shows a frazzled, white-coated scientist chasing a herd of cows. The ad's narrator -- Neumannn himself -- states that "this scientist is hard at work spending your tax dollars. It's all part of a government study on cow gas. You know, the kind of gas that comes from . . ." -- at which point the viewer hears the sound of flatulence. Neumann notes that Feingold voted for the study, wryly adding that "this smelled like Beltway waste to me, so I wrote a bill that killed the funding for this ridiculous program."

Pretty crafty advertising from a guy who's so square he's divisible by four. ("My idea of heaven," the nerdy former math teacher once said, "is a wall with numbers on it.") Yet it fits into Neumann's strategy of portraying himself as a populist budget-cutter and Feingold as an elitist big spender. No dig is too small: Neumann has taken to calling his opponent "Russell," which he says is more appropriate for a Rhodes scholar and Harvard Law graduate. "Russ," he says, connotes a guy who's a Packers fan and goes deer hunting.

Neumann isn't bothering with many campaign appearances, choosing instead to devote his time to raising money for radio and television ads -- which is probably a good idea. Neumann is notoriously abrasive (it's no surprise that he coaches his son's football team) and no Clinton of a schmoozer.

Feingold, by contrast, is all polish. He visits each of Wisconsin's 72 counties every year and has an easy familiarity with the voters (he was elected to the state Senate at age 29). Asked about the tightening in the polls, he professes not to be concerned, telling the Milwaukee Journal Sentinel, "I kind of like the underdog role anyway." This is plausible -- Feingold wasn't favored to win either the Democratic primary or the general election in 1992 -- but glosses over the fact that, as the incumbent senator, he should hold a comfortable lead. A recent GOP poll showed him at 42 percent, a sure sign of vulnerability.

One of Feingold's problems is his devotion to campaign-finance reform. This issue won't win him many votes -- people find the subject only slightly more interesting than Italian pension reform -- and, to be true to his principles, he agreed to limit his campaign spending to $ 3.8 million, which comes out to one dollar per voter. While Neumann has also agreed to this limit, it is worse for Feingold, who as the incumbent could easily raise more.

Another problem for Feingold is that the state's Republican governor, the popular Tommy Thompson, is running far ahead of a weak Democratic opponent. Republicans think Thompson's coattails -- which four years ago led to a GOP-controlled state assembly for the first time since 1970 -- just might sweep Neumann into the Senate.

If Neumann does indeed prevail, he'll owe something to Thompson, but also to Bill Clinton. A recent private poll found that 33 percent of Wisconsin voters are "likely" to want to send a message to Clinton for his conduct. This is bad news for Feingold, even though he's never been particularly close to the president and isn't expected to have him in for a campaign visit. But the Big He will nonetheless loom over the campaign.

With Democratic turnout likely to be down, Neumann's decision to make partial-birth abortion one of his top issues could decide the race for him. In addition to a large Catholic population (almost 30 percent of the state), Wisconsin has one of the most active right-to-life movements in the country. Earlier this year, pro-lifers waged a campaign to recall Feingold and Herb Kohl, the state's other senator, for their votes against the partial-birth-abortion ban. The effort failed, narrowly, but the pro-life activists collected nearly 350,000 signatures.

National pro-life groups hope to use this energy to bring new voters to the polls and unseat Feingold, who is one of their least favorite politicians. Why? On the Senate floor in 1996, Rick Santorum, a Pennsylvania Republican, asked Feingold whether a woman and her doctor should be allowed to kill a baby who is slated to be aborted but who is accidentally delivered. Feingold responded, "That is a question that should be answered by a doctor and by the woman who receives advice from the doctor." Ever since, Feingold has tried to clear up this apparent acceptance of infanticide -- he had the Congressional Record transcript of the exchange altered -- but Neumann and his antiabortion allies will be reminding voters of Feingold's statement right up to Election Day.

For all the differences between the two candidates, both have maverick tendencies that appeal to the state's anti-establishment tradition. Feingold has taken high-profile stances opposing the White House on trade with China, troops to Bosnia, and Alan Greenspan's reappointment as chairman of the Fed. Similarly, Neumann's independence, and his single-minded crusade against the federal debt, has made him a pariah among tax-cutting conservatives. The Wall Street Journal editorial page, for example, has repeatedly panned his debt-reduction plan. Neither is Neumann terribly popular among his House GOP colleagues: He was one of the few not to support Newt Gingrich's reelection as speaker. And even Rush Limbaugh, with Neumann as his guest, criticized the congressman's economic agenda. (Neumann tried to turn this to his advantage, saying, "This is a wonderful, wonderful country, when a country kid from East Troy, Wisconsin, can be on a show with someone as important as Rush Limbaugh.")

Neumann's populism is occasionally tacky, but it just may work: Feingold was little known when he was elected, and he has been relatively quiet throughout his term. Aside from the partial-birth-abortion controversy, he hasn't done much to alienate state voters. Still, Monicagate will depress Democratic turnout, and Feingold is vulnerable to a barrage of negative ads -- which has presented Mark Neumann with a genuine chance to stage an upset.

Matthew Rees is a staff writer for THE WEEKLY STANDARD.