Gretchen Whitmer of Michigan Was Overlooked. Not Any Longer.

She won her first primary election for the State House of Representatives less than three years after graduating from law school, kick-starting her political ascent that culminated with her becoming the first woman to lead a party caucus in Michigan’s Senate.

Republicans have criticized Ms. Whitmer for being a lifelong politician and failing to sponsor significant legislation while in the statehouse. They have also said that in her next job after leaving the legislature, as Ingham County prosecutor, she failed to aggressively investigate Lawrence G. Nassar, the former Michigan State gymnastics doctor who was later convicted of charges of sexual molestation and child pornography.

Ms. Whitmer has said she pursued the necessary charges based on the information she was given at the time, and the Nassar case was eventually taken out of her jurisdiction. She also notes that she made several reforms to the prosecutor’s office in her six-month tenure, including opening a unit dedicated to investigating domestic violence.

Political experts in Michigan point to the Medicaid expansion as a defining moment for her bipartisan credentials. Some Democrats in 2013 were torn about whether to work with the Republican governor, Rick Snyder, such a key legislative accomplishment, but Ms. Whitmer gained fans throughout the state for her willingness to put policy over politics.

Debbie Stabenow, the Michigan senator who won re-election Tuesday, credits Ms. Whitmer for helping women secure victories across the ticket. Ms. Stabenow said it was especially important to do so by emphasizing their job qualifications, not their gender.

“Sooner or later in American history this moment was going to come, where women were stepping forward and being recognized as the most qualified candidate,” Ms. Stabenow said, as Aretha Franklin’s “R-E-S-P-E-C-T” blared from Ms. Whitmer’s campaign bus on Tuesday. “And that didn’t happen because we were in a back room and planned this together, but because each of us ran on our own merits.”

The next song in the queue was Ms. Whitmer’s favorite: Lizzo’s women’s empowerment anthem, “Good as Hell.”

“Boss up and change your life,” the future governor sang. “You can have it all, no sacrifice.”