… Midterm elections are different from those that take place in presidential election years. And midterm elections that take place with an unpopular president in office are very different from presidential election years that have two historically unpopular candidates at the top of the major-party tickets.
Republican congressional candidates in 2016 may not have gotten much help from Trump, but they got a big boost from someone else: Hillary Clinton. CONT.
Harry Enten, FiveThirtyEight