On her website, Ms. Lake pledges to support all forms of birth control, as well as state government programs to help pregnant mothers seek alternatives to abortion, such as adoption, and provide resources for parental support and guidance. She also says fathers must be “held accountable.”

Some 90 percent of Arizona voters said abortion should always be legal, or should be legal in some circumstances, according to a survey conducted in early September by the Phoenix-based firm OH Predictive Insights. And 45 percent said that a candidate’s stance on abortion had a strong impact on their vote.

“It’s just scary,” said Andrea Luna Cervantes, a reproductive-rights activist in Phoenix. “Because you’re a woman, because you’re a person who can give birth, your rights can be just stripped.”

Ms. Cervantes said she got involved in abortion-rights activism after seeing people she knew face pregnancies with few resources or options other than carrying them to term. She said she planned to vote for Ms. Hobbs, but some family members back in Yuma were unconvinced.

The ban struck a chord with some Indigenous voters, who make up 5 percent of the state’s population. Anjeanette Laban, a member of the Hopi Tribe, said reproductive health care was already dangerously scarce and distant. She saw the end of abortion access in Arizona as another colonial oppression. She said that she knew little about the candidates running, but that the abortion issue would determine her vote.

“They’re still trying to dictate what we can do, how they can limit us,” she said.

In recent weeks, Ms. Hobbs has been leaning into the issue of abortion in email blasts to supporters, and the Arizona Democratic Party has released a new television ad slamming Ms. Lake for saying she did not believe abortion should be legal.

“Since Roe v. Wade was overturned, Arizona has reverted back to a 100-year-old law that criminalizes abortion, and Kari Lake — she supports that,” Chris Nanos, the Pima County sheriff, says in the ad.

After the abortion ban ruling, Ms. Lake called Ms. Hobbs “radical” on the issue during an interview on Fox News. On Monday, she emailed supporters keeping up her critique of Ms. Hobbs on immigration. The subject line was “Open Borders Katie.”