 Former President Donald Trump has chosen Republican Senator J.D. Vance of Ohio as his vice presidential running mate. NPR's Danielle Kurtzleben is at the Republican National Convention in Milwaukee. She says Vance is 39 and a first-term senator. Vance is a convert, and converts can be really powerful messengers. And now that Vance supports Trump, he's a former Never Trumper and a relatively young Never Trumper. It's possible that J.D. Vance could reach a new voter or two.