With their expected primary fewer than four months away, the race between incumbent Reps. John Dingell and Lynn Rivers for the Democratic nomination in Michigan's 15th Congressional District is quickly heating up. Dearborn's Dingell called on Rivers (D-Ann Arbor) yesterday to put an end to negative campaigning in the two incumbents' battle to keep their own jobs.

Dingell said the two candidates should agree to make several joint appearances in front of voters before the Aug. 6 primary and that the candidates and their supporters abstain from mentioning their opponent by name - focusing solely on their own record.

"I've been running for Congress for a few years and I don't want to run in a way that demeans me, my office or my friends," Dingell 75, a 24-term incumbent and the House's longest-serving member, said.

The two incumbents, who currently represent separate congressional districts, saw their districts combined last year when the Republican-controlled state Legislature and GOP Gov. John Engler redrew the state's congressional districts. The state Democratic Party is challenging the new district lines in federal court, but redistricting challenges in court usually do not prevail.

Dingell campaign manager Lon Johnson said the veteran congressman asked Rivers, a four-term incumbent, to follow the same campaign guidelines she offered to her Republican opponent in 1996, Joe Fitzsimmons, who declined the offer.

The mutual agreement to abstain from negative campaigning is a relatively new tactic in election campaigns.

"We are specifically asking the Rivers campaign to agree to what they thought was a good idea in 1996 - that each candidate talk about what they've done and what they're going to do for the 15th district - and in addition to that, instruct their allies to do the same," Johnson said.

The Rivers campaign did not return phone calls yesterday seeking comment and Johnson said he had received no answer to the proposal from Rivers.

The winner of the Dingell-Rivers match-up will likely face Dearborn resident Martin Kaltenbach, who is expected to be unopposed in his quest for the GOP nod.

Sierra Club endorses Rivers

The Rivers campaign received a significant boost yesterday with the addition of the environment-oriented Sierra Club's endorsement.

"I would say the people of the 15th district have a choice between someone lukewarm on the environment and someone rock solid on the environment," said Dan Farough, the Michigan Sierra Club's political director.

Farough criticized Dingell for voting for the 1990 Clean Air Act only because he feared an electoral backlash, and accused him of stalling it as chairman of the House Energy and Commerce Committee. Dingell countered that garnering support for the bill was difficult but that he was instrumental in passing it.

"It took us 13 years to produce the bill, but I got it passed in the House after only 13 hours - 428 to 6," Dingell said.

Dingell's strongest support comes from labor with backing from the Michigan AFL-CIO and Teamsters in addition to several other unions and police and firefighters' organizations.

Rivers' main backing comes from social interest groups, such as Planned Parenthood, the Brady Campaign to Prevent Gun Violence and the Human Rights campaign.

LSA senior Eric Feldman, former chair of the University's chapter of College Democrats, said the nation's arguably most watched congressional primary will not just be a test of how well Dingell and Rivers campaign.

"We'll see if the party is more motivated by candidates who run on socially liberal issues or economically liberal issues," he said.