text:  Republican presidential nominee Donald Trump, meanwhile, has made his decision on a vice presidential running mate. Trump choosing U.S. Senator J.D. Vance of Ohio to stand with him as he seeks to return to the Oval Office. NPR's Don Gagne is more on the president's pick. They're both known for being really combative, but also there's generational balance. There's hope, no doubt, that Vance will have appeal to younger voters.