Looking at the Dolphins roster, our friend Melifonwu is a free agent. He played more games than both Joseph and Branch. Would be good depth and is familiar with the system.
Nixon is a pretty strong comp. Senator from California > Vice President> loses as incumbent Vice President> comes back 8 years later and wins. Nixon would probably have run in 64 if Johnson was an unpopular as Trump is.
Republicans seem to think Dems will protect their own the way they do. Dems threw their incumbent under the bus because he was old. They forced Franken out over a picture. They aren’t going to back Clinton who hasn’t been president in 25 years. Obama is the new leader of the party.
Massie ran unopposed last election. When he has been opposed, it's been an R+30 district. At best you probably get it R+15 which can still have its benefits but I wouldn't get my hopes up of flipping that seat.