How women's issues became Melinda Gates' issue

Melinda Gates told me in an interview earlier this year that she initially eschewed a focus on women's issues, seeing it as one of the "soft" areas typically reserved for female philanthropists.

Driving the news: Gates said she realized that women's issues were actually the key to the other areas that she is passionate about: global health, education and economic equality.

"If you invest in a woman we totally know from great research she invests in everybody else. ... She not only lifts her kids and her family but she lifts up her community, which lifts up society, which lifts up her country."

Similarly, contraception turns out to be not just a women's issue, but the key to a country's overall economic empowerment. No country in the last 50 years has made the transition from low income to middle income without allowing access to birth control, Gates said.

"Contraceptives are the greatest anti-poverty tool we have in the world. More than 90% of U.S. women use them. We believe in them and we should make sure that all women have access," Gates said during an interview during the San Francisco leg the tour for her book: The Moment of Lift: How Empowering Women Changes the World.

Why now? While both she and Bill Gates have generally stayed out of partisan U.S. politics, Melinda Gates chose to speak out after the Trump administration proposed to gut funding for contraception globally.

"When I saw a budget come out from the administration that proposed extraordinarily few resources for contraceptives around the world, I believe so fundamentally in that issue, I knew I had to speak out and I did and I have ever since then."