Pien Huang is a correspondent on the Science desk. She was NPR's first Reflect America Fellow, working with shows, desks and podcasts to bring more diverse voices to air and online.
The primary runoff in South Carolina between Sen. Darline Graham and Rep. Ralph Norman is another test of President Trump's influence. He's backing Darline, sister of the late Sen. Lindsey Graham.
Fio Geiran, Christopher Intagliata, Adrian Florido
NPR's Adrian Florido talks with Ken Rider of the California Energy Commission about a new rule for more efficient tires, which could cut the greenhouse gas emissions that cause climate change.