Even those who applaud Mr. Steele’s vision of a more inclusive Republican Party wonder if he can execute it. “Does he have the mettle to wage that type of fight?” asked Benjamin T. Jealous, the president of the National Association for the Advancement of Colored People.

Mr. Steele says that he does, but that he is entirely willing to risk failure. “I always found it interesting that people would cast aspersions on failure, as if it were a bad thing,” he said.

For decades, top Republican officials have looked at Mr. Steele and seen the promise of minority votes. He was recruited in the 1980s by Lee Atwater, a strategist who was the first of many excited by the charismatic, black Roman Catholic.

Outside politics, Mr. Steele struggled. He tried the priesthood but left as a novice. Later he practiced law for seven years in Washington (after passing the Pennsylvania state bar, he said), then started a consulting firm that made so little money that he almost lost his home.

But in the weak Maryland Republican Party, in a state that is 30 percent black, Mr. Steele was an instant hero. (The moment she saw him, said Joyce Terhes, the former state party chairwoman, she knew he was a keeper.) He zoomed from volunteer to state chairman to running mate in a race for governor.

Before the 2002 election, The Baltimore Sun published an editorial saying that because of his lack of experience, Mr. Steele brought “little to the team but the color of his skin,” outraging him and his supporters.

Image Michael Steele in the television studio of the Republican National Committee in Washington. Credit... Stephen Crowley/The New York Times

When Mr. Steele became lieutenant governor, he found himself among the highest-ranking black Republicans in the country, instantly embraced by President George W. Bush and his allies. Speaking to black groups, he was often the only Republican in the room, and in some Republican gatherings, the only African-American.