Tudor Dixon went from a relative unknown to the G.O.P. nominee for governor in Michigan.

STERLING HEIGHTS, Mich. — Tudor Dixon, a former conservative media personality and now the Republican nominee for governor in Michigan, paused during a radio interview the morning after she won a crowded, chaotic primary. She wanted to acknowledge one factor that helped catapult her to victory: a late-breaking endorsement from former President Donald J. Trump.

“We wanted to make sure that we could bring the party together,” Ms. Dixon said on Wednesday. “We wanted to make sure that we would be solid on the Republican side because we knew going into the general, we have to win independents and we have to win some Democrats.”

But even after a primary where Ms. Dixon beat her opponents by a wide margin, attracting many voters beyond conservative Republicans seemed a formidable challenge as Ms. Dixon prepares to face Gov. Gretchen Whitmer, who is running for a second term and enjoys the support of an energized base seeking to protect abortion rights.

Ms. Dixon, a relative unknown who was previously an executive at her family’s steel company, suffers from a lack of name recognition in the state, even within her own party. And though she spoke Wednesday about the importance of Republican unity, there was still one sign she could struggle to bring the party together: After the primary results were tallied on Tuesday, one of her Republican opponents, Ryan Kelley, said he refused to concede.

Ms. Dixon will also have to contend with broader political forces. The sweeping rejection by Kansas voters on Tuesday of a constitutional amendment that would have let state legislators ban or significantly restrict abortion has further elevated issues of reproductive rights, which could be an especially potent issue in Michigan in the general election. Ms. Dixon has said that abortion should only be allowed if necessary to save the life of a mother, and that she would not support exceptions for rape or incest.

“This is going to be an epic battle,” Ms. Dixon told supporters in a victory speech on Tuesday evening.

In interviews across the state this week, Republican primary voters said they were fearful of Ms. Whitmer winning a second term but uneasy about Ms. Dixon’s ability to unseat her.

Ms. Whitmer has drawn criticism from conservatives over rising inflation, her handling of the coronavirus pandemic and the perpetually run-down state of Michigan’s roads. But the governor is entering the general election campaign with solid popularity in the state — her approval rating was 55 percent in a July survey conducted for The Detroit News — and a base of Democratic voters who have been outraged by a looming threat to abortion rights.

Abortion is legal in Michigan, but conservatives are pushing to enforce a 1931 law that bans the procedure in nearly all cases. Ms. Whitmer has seized on the issue and made it a centerpiece of her campaign.

Dozens of voters interviewed in Michigan this week said that they were supporting Ms. Dixon largely because of Mr. Trump’s endorsement.

At an elementary school in Sterling Heights, Mich., on Tuesday, two Republican voters struggled to remember Ms. Dixon’s name, though they intended to cast a ballot for her. One man said he was going to vote for the candidate Mr. Trump had endorsed — “the lady,” he said, though he didn’t know anything about her.

Fred Starcher, 61, a truck driver, said he had only recently heard of Ms. Dixon, but was hopeful that she would ease the financial burdens of the working class. When gas prices were at their peak recently, he said, he was paying at least $300 a month to fill up his Jeep, dipping into his savings to make ends meet.

“We’re almost depleted,” Mr. Starcher said. “I think she’d be for the blue collar. A Republican governor would make a difference.”

Don VanSyckel, a member of the board of commissioners in the Republican stronghold of Macomb County, said he had favored one of Ms. Dixon’s opponents in the primary, and remained doubtful that Ms. Dixon was qualified for the job.

“Michigan needs help. We need to bring back our small businesses and infrastructure,” he said. “I don’t think she has the depth of managerial experience.”