DETROIT - Six months ago, U.S. Rep. David Bonior, a Mt. Clemens Democrat, thought he might be House majority leader now, and next in line to become speaker of the House. Today, he is planning to leave Congress and throw his energies into a tough campaign for a job nobody ever knew he wanted - governor of Michigan.

“It's something I've been thinking about for some time,” said Mr. Bonior, who represents Detroit's northeast suburbs, and whose politics are very close to Toledo Congresswoman Marcy Kaptur's. “I'm very, very excited about the opportunity to change this state around,” he said over breakfast on the way to a fund-raiser in Detroit.

Some cynics think he's running mostly because the seat in Congress he's held since 1977 is about to disappear. Michigan unexpectedly lost a seat when the census results became known, and the Republicans who control redistricting have their knives and calculators out to erase the highly partisan Mr. Bonior from the map.

The betting is that his district will be transformed into a rock-solid Republican one, tailor-made for Secretary of State Candice Miller, who has to leave her job because of term limits. Mr. Bonior, who turns 56 in June, doesn't deny redistricting was a factor in his decision, but claims, less convincingly, that he could win whatever district was left for him to run in.

“But I have been thinking a lot about [running for governor] ever since my wife Judy and I walked 300 miles across the lower peninsula,” which got him thinking more about his state and its problems, he said. Mr. Bonior's book about that 1997 experience, “A Walk to Mackinac” is to be published this year by the University of Michigan Press.

Without doubt, Mr. Bonior has been one of Congress' most powerful and effective legislators, a principled man who hasn't been afraid to tangle with the leadership of his own party, as he did over NAFTA, the North American Free Trade Act, which he bitterly opposed. He can justifiably claim to have started the process that brought former House Speaker Newt Gingrich (R., Ga.) down, by attacking him over a series of alleged ethical violations, some serious and some petty.

Though he is often portrayed as a tool of labor unions, he has also proven a formidable vote-getter in his own right. His district has changed over the years, and now has a mainly Republican base. But by aggressive constituent services, a highly visible environmental record and an impressive money-raising machine, Mr. Bonior always has gotten re-elected, often over tough and well-financed Republican opposition.

Four or eight years ago, the gubernatorial nomination might have been his just for the asking. But ironically, he's now an underdog, running third in early polls behind Jim Blanchard, governor from 1983-91, and Michigan Attorney General Jennifer Granholm. Mr. Bonior shrugs. “Polls show 40 percent of the people don't know who I am yet. Those numbers will go up as they learn more about me.”

What they will learn is that Mr. Bonior is an almost quintessential product of industrial Detroit, a man of Polish ancestry who was born in Hamtramck and grew up in the blue-collar suburb of East Detroit, the son of a printer and auto worker. Devoutly Catholic, he became a seminarian in high school, though he later decided not to become a priest. He played football in college (Iowa) and served in the U.S. Air Force.

After a stint as a probation officer, he was elected to the Michigan legislature in 1972 and to Congress four years later. Though he has been a congressional champion of blue-collar workers, his other main issue always has been the environment. He's fought to clean up rivers and build bike trails. He is best known by many for passing out hundreds of thousands of white pine seedlings during his campaigns.

Without doubt, he will be formidable. The UAW and other unions are certain to be strongly in his camp - and they are still the biggest factor in a Democratic primary. “Forty percent of the vote is what you need to win,” noted Melvin “Butch” Hollowell, a Detroit attorney who supports Ms. Granholm. “I think Bonior is (her) stronger opponent,” said Mr. Hollowell, who is running for Secretary of State.

Mr. Hollowell has nothing against David Bonior, and will have no problem supporting him should he win the nomination. But he and other Democrats worry that because of his strong union identification and liberal voting record, he may be the least electable candidate statewide in November.

The congressman dismisses that. “The key to elections in this state is Macomb County, and I get votes there that no other Democrat does,” he notes accurately. One big unknown: Unlike the majority of his fellow Democrats, Mr. Bonior is anti-abortion, though he would make exceptions for rape, incest, and the life of the mother.

Michigan Democrats do seem headed for what may be their most power-packed gubernatorial primary ever. That could be a net plus for the party, which is seeking to regain the governor's office after a dozen years in the cold.

But if the election turns bloody, nasty, and divisive, the real winner may be the presumed Republican nominee, genial Lt. Gov. Dick Posthumus. Naturally, all three big-name Democrats vow a statesman-like candidacy based on the issues. Don't bet on it staying that way.

Jack Lessenberry is The Blade's ombudsman and a member of the journalism faculty at Wayne State University in Detroit. E-mail him at OMBLADE@aol.com or call 1-888-746-8610.

First Published March 24, 2001, 6:13 p.m.