Last month in her Lansing campaign office, Ms. Whitmer outlined some of the defining contours of her life in public service. She credited her parents, a Michigan power couple who worked in state government, with instilling in her a desire to give back to others. She also cited two life-changing experiences as the motivating forces behind her pragmatic approach to policymaking: caring for her dying mother in the early 2000s while she was nursing her first child and being sexually assaulted in college.

Ms. Whitmer described the sexual assault in an emotional speech on the floor of the State Senate in 2013, when she opposed the so-called rape insurance bill, which banned insurance coverage for abortion in private health plans unless women purchased a separate rider. The bill passed over her objections, but she views it as an example of how her values inform her political decisions.

“I’ve come to appreciate that these experiences are what compels me to just come in and fix problems,” she said. “It eliminates my patience for anyone who wants to politicize an issue instead of just rolling up their sleeves and getting to work.”

Republicans struggled to find a consistent line of attack against Ms. Whitmer. Mr. Schuette, who heavily spent his own money in the governor’s race, tried to tie Ms. Whitmer to the tenure of former Gov. Jennifer Granholm, whose administration struggled with a slumping economy and the financial collapse of Detroit during her two terms.

Mr. Schuette even called Ms. Whitmer by Ms. Granholm’s name in a recent debate, though he quickly corrected himself.

“Maybe Bill Schuette will finally learn my name,” Ms. Whitmer said at a campaign stop on Election Day.

The most lasting criticism of Ms. Whitmer came from Mr. El-Sayed, her primary opponent who later endorsed her. In a recent interview, Mr. El-Sayed said “it’s no secret” that his definition of a progressive differs from Ms. Whitmer’s. He also said Ms. Whitmer’s establishment ties significantly helped her in the primary.