Former Army Capt. Sam Brown is heavily favored in the Nevada GOP Senate primary to take on Democratic incumbent Sen. Jacky Rosen, but one wild card remains: Donald Trump. Republican primary voters are already casting early ballots across Nevada, but the question of whether the former president will make an endorsement in the state’s must-watch Senate contest still hangs over the race. Jeff Gunter, a dermatologist who served as Trump’s ambassador to Iceland, has been making the case that...