In his first speech as vice presidential running mate alongside presumptive Democratic presidential nominee Kamala Harris , Minnesota Gov. Tim Walz talked about his familys past struggle to have kids.

When my wife and I decided to have children, we spent years going through infertility treatments, Walz said during a rally in Philadelphia.

I remember praying every night for a call for good news, the pit in the stomach when the phone rang, and the agony when we heard the treatments hadnt worked, Walz said. It wasnt by chance that when we welcomed our daughter into the world, we named her Hope.

Walz, a father of two, first started telling the story about his familys fertility struggles earlier this year, after the Alabama Supreme Court declared that embryos are people in a controversial February ruling that briefly jeopardized access to the fertility treatment known as in vitro fertilization.

Days after the courts decision, Walz said he knew IVF would become a foundational campaign issue this November because he and his wife, Gwen Walz, had been through the experience.

I got a very narrow skillset, but having the zeitgeist through these things, Im telling you, its a big thing, Walz, the chairman of the Democratic Governors Association, said in a roundtable interview with reporters in Washington, D.C., in response to a question from HuffPost.

In full disclosure, my wife and I used Mayo Clinic reproductive services, and my daughter Hope was named Hope for a reason, he continued. Because married for eight years, no children, wanting children. We got Hope because of this type of stuff. I cant be the only one thats there.

Without going into any detail about the treatments, Walz shared more in an interview with the Minnesota Star Tribune the following month, when he recounted his wife calling him crying after theyd spent years undergoing treatments at the Mayo Clinic in Rochester, Minnesota.

I said, Not again, Walz told the paper. She said, No, Im pregnant. Its not by chance that we named our daughter Hope.

Hope Walz is now 23 and her brother, Gus Walz, is 17. (Tim Walz has not shared the specific treatment he and his wife received.)

At the time of the interviews, Walz was pushing the Minnesota legislature to enact extra protections for IVF in the state, which is the same thing the Alabama legislature wound up doing as Republicans across the country realized their push to restrict abortion had collided with a fertility treatment responsible for 2% of births in the U.S.

The Alabama Supreme Court ruled that the frozen embryos created through IVF should be considered children, meaning their destruction during fertility treatment was legally murder, prompting some clinics to cease offering IVF. The ruling came about after Republicans in the Alabama legislature enacted laws anticipating the Supreme Courts overturning of Roe v. Wade, the 1973 decision establishing a federal right to abortion, in 2022.

Walz emerged as a vice presidential candidate after President Joe Biden dropped his reelection bid last month and Democrats elevated Vice President Kamala Harris to the top of their presidential ticket. Democrats embraced his description of former President Donald Trump and his running mate, JD Vance, as weird, and the Harris campaign used it with a particular focus on Republicans opposition to abortion, which they have said extends to IVF.

Trump has insisted that Republicans support IVF, though most Senate Republicans voted against a Democratic bill designed to protect access to the treatment earlier this year.

In February, Walz said Republican statements in support of IVF were a sham.

No one believes that. For Christ sakes, Tommy Tuberville doesnt even know what it is, like no idea what it is, Walz said, referring to the junior Republican senator from Alabama. This things going to be huge. Im telling you this reaches into families. This is fundamentally important.

Walz again described his family relying on fertility treatments, which he described as things like IVF, during an online fundraiser last week, before he had been selected for the VP job.

The Harris campaign on Tuesday described Walzs familys experience as cementing his commitment to ensuring all Americans have access to this care but declined to provide details about the specific treatment they received.

Reproductive freedom has been a top issue for Democrats since 2022 and helped stem their losses in midterm elections that year. The Harris campaign clearly hopes to keep it front and center during the remaining 90 days of the presidential campaign, and Walz may be an effective messenger.

During Tuesdays rally, Walz framed the issue as a matter of personal freedom.

In Minnesota, we respect our neighbors and the personal choices that they make, even if we wouldnt make the same choice for ourselves. There is a golden rule: Mind your own damn business, Walz said, leading to chants from the crowd. When the vice president and I talk about freedom, we mean the freedom to make your own health care decisions.