HOOVERSVILLE, Pennsylvania — If you are a longtime resident of Pennsylvania, it still is a bit of a jolt to the senses to drive through what was once coal country and see an oversized, cheery, red billboard sitting along U.S. 30 reading “VOTE REPUBLICAN.”

However, it is a reminder of how much the people who live in these old industrial and coal-rich counties have shed the local Democratic politics of their upbringing. Voter registration numbers, as we shall see, show as much.