Wayne County Executive William Lucas, a Republican who wants to become the nation's first elected black governor, likes to tell the story of a college track meet in which another black miler pulled ahead of him near the finish line.

Lucas' teammates -- all white -- started to cheer him on wildy. "Come on Lucas," they urged. "Don't let that black SOB beat you!"

Lucas recites the anecdote, in his disarmingly soft Caribbean lilt, as a case study in colorblindness. "Most people, after they get to know you, forget what race you are," he said.

Next year, he will put that generous reading of human nature to the test in a state race that is a rarity -- one with the potential to send political ripples well beyond Michigan's borders.

In just five months as a Republican, Lucas, 58, has become the Great Black Hope of his adoptive party. His switch has come when many Republicans -- and not a few blacks -- think that the monogamous bond between blacks and Democrats is beginning to fray at the edges. Lucas has been recruited by the GOP to be the proof of that theory.

"There is a growing frustration that blacks have with the Democratic Party right now," said Linda Williams, senior analyst for the Joint Center for Political Studies, which studies black voting behavior. "There is a sense that as the Democrat Party searches for a new identity, it isn't paying any attention to blacks."

"You've got blacks feeling like they're taken for granted by the Democrats; and you've got an expanding black middle and professional class, both of which gives us some openings," says Lee Atwater, a Washington-based GOP consultant working on the Lucas campaign. "What Republicans need to bring it all together is an elected leader. That's where Lucas comes in."

Lucas' bear-hug treatment from both the national and state GOP appears to have survived the first setback of his still officially unannounced gubernatorial candidacy -- at least so far.

Detroit newspapers reported last month that as executive of Wayne County, which consists of Detroit and its western suburbs, Lucas approved a $23 million county building-renovation contract in 1984 knowing that his chief of staff, Dennis Nystrom, was part owner of a company that stood to receive some of the work.

The charges briefly froze the Lucas bandwagon within GOP leadership circles here, and they could do more lasting damage if an investigation under way by the Democratic-dominated county board of commissioners fleshes out or expands the case. Although Lucas seems to have survived the crisis, there is palpable concern among GOP leaders that, as one put it recently, "if another shoe drops, his candidacy is dead."

Meanwhile, Lucas has been accused of no illegality. He notes that the deal was never executed. And he says he had awarded the contract on a low-bid basis. Moreover, since the conflict-of-interest charge arose, he has picked up several important political endorsements in the western part of the state.

But endorsements only go so far in a political campaign that must manuever the tricky currents of racial voting. Will white Republicans support a black? Will black Democrats cross over for a Republican? Both questions probably won't be answered until Election Day. Polling in such races has proven of limited use; respondents tend to give socially acceptable answers.

Lucas' low-key speaking style, his law enforcment background (New York City police and the Federal Bureau of Investigation), his Horatio Alger background (son of Caribbean immigrants who ran a grocery store in Harlem; orphaned at age 12), and his bootstrap conservatism win him supporters in his frequent speeches to GOP and business groups around the state.

"All my life people have been accusing me of being a closet Republican," says Lucas, who as Wayne County executive has taken on the public employe unions and sold the county hospital to private interests (a move that sparked an unsuccessful recall campaign by a militant black group in Detroit). "Well, I finally realized they were right," Lucas said about his party switch.

Even among Lucas' white admirers, though, there are many who take a dimmer view than he does of the human potential for colorblindness. "Ever hear that country song, 'What goes on behind closed doors,'?" asked real estate agent Ronald Lilly, who heard Lucas address a Rotary luncheon in Rochester, Mich. "People say one thing, but when they get into a voting booth, it's something else. A lot of people in this state moved out of Detroit to get away from the blacks. They're going to vote for Lucas?"

Still, Lucas remains a favorite in any GOP primary, in part because none of his opponents has a statewide base, in part because he can argue that he alone can cut into Gov. James J. Blanchard's (D) strength among blacks -- 12 percent of the state electorate -- in part because he has lined up some of the the best GOP talent money can buy: Atwater, media consultant Roger Ailes and pollster Robert Teeter.

His prospects in a fall race against Blanchard are much chancier. After feeling great heat in 1983 for raising the state income tax in the depth of a recession, Blanchard has rebounded handsomely, as has the state economy. Taxes are on their way back down to their pre-1983 levels.

Lucas has proposed that taxes be cut further, and that sizes up as a key battleground next year.

The other, of course, is the black vote. Can a conservative Republican, who is also black, attract it?

Rep. John Conyers Jr. (D-Mich) says that he thinks not. "Blacks here consider Lucas a turncoat," he said. "He is to the right of Attila the Hun. He is just being used by the national Republican Party to try to create a new image, and blacks know it. The truth is that Republicans want blacks in their party like I want holes in my head."

Conyers said he would actively oppose Lucas in the governor's race; Mayor Coleman Young, the strongman of Detroit politics, is expected to do the same. On the other hand, history shows that when a "first" candidate of any racial or ethnic group runs a credible campaign for high office, group pride rallies. Teeter and Atwater say they think that Lucas can attract at least a third of the black vote.

That would be a level that many white Republicans routinely achieved in black communities through the end of the 1950s. A generation later, it would be a breakthrough.