Count the House races, and you’ll get a pretty good idea of whether the House will flip in the fall. No, you can’t be entirely certain how an individual toss-up contest is going to turn out in November. But you can arrive at a ballpark assessment of House changes right now by looking at three baskets of districts and how similar ones behaved in previous midterms.
There are 25 Republican House members representing districts carried by Hillary Clinton in 2016 (up from 23 before Pennsylvania drew a new congressional map). Almost one-third of those members, eight, are retiring. Given the current political polarization, the normal midterm dynamic (which punishes the president’s party) and the added risk of losing open seats, it’s likely that most of those 25 GOP districts will flip party control.