Nashville, Tennessee — A line snaked around the first floor of the posh Four Seasons hotel in Nashville Monday evening as wealthy conservative donors eagerly waited their turns to ride an elevator upstairs to hear a special guest speak: the vice president of the United States.  JD Vance headlined a closed-door gathering for the spring summit of the Rockbridge Network, a secretive donor group that Vance co-founded in 2019 during his stint as a private investor. According to a source in the room,