A Nazi party dropout who founded a splinter group dedicated to white supremacy has stunned Michigan Republicans by winning the GOP nomination to run for Congress from a suburban Detroit district.

Gerald R. Carlson, founder of the National Christian Democratic Union, which he terms a "political party for white Americans," won by 3,715 votes to 3,037 or 55 percent in Tuesday's Republican primary to defeat James Cayhill, public safety commissioner of suburban Woodhaven.

Carlson will oppose Rep. William Ford in the November election for the seat representing Michigan's 15th Congressional District, a largely Blue-collar area west and southwest of Detroit.

Republican leaders, who thought that Cayhill would be serious opposition for Ford, who was first elected to Congress in 1964, were shocked by Carlson's victory.

"That's the people's choice, but he's not getting any encouragement from me." Republican state chairman Mel Larson said.

"This guy is a total jerk," said Pat Ganzberger, 15th District Republican Party chairman.

"No, he's not our candidate. No I'm not going to support him. I'm going to support James Cayhill as a write-in."

Cayhill acknowledged that he plans to run in the general elections as a writer-in. "I won't give up," he said. "I know what's right and what's wrong and I won't give up . . . It's a sick situation in this country."

The Republicans charged that Carsons' victory resulted from crossover voting in Michigan's open primary, and they blamed the United Auto Workers and the Democratic Party for the embarrassment.

Sam Fishman, director of UAW political operations in Michigan, called the GOP charge "a dastardly lie" and said the Republicans were "trying to cover up their own inability to keep control of their party."

Carlson, an electrician though to be in his late 30s, was not available for comment. The telephones at his headquarters, which during the campaign were equipped with taped disconnected.

In a voters guide published by the Michigan League of Women Voters, Carlson of Michigan and an Air Force veteran who had "lived in clean and orderly European cities and realized that Negroes are the main cause of our degeneration."

He also said that productivity lags in this country because blacks "do not work like white people; in addition they sabotage. Corrupt communistled unions protect Negroes."

Carlson told a reporter about a year ago that before forming his own group, he belonged to the National States Rights Party, the Ku Klux Klan, the John Birch Society and the Nazi party.