… The particular problem for House Republicans is this: when Congress is unpopular, voters don’t punish all House incumbents. Instead, they direct their dissatisfaction primarily at majority-party House incumbents. …
[David] Jones finds that a 10-point decrease in approval costs majority-party House incumbents 4 points at the poll. This effect is larger in swing districts and has been getting larger over time, as the parties have polarized. [cont.]
John Sides, George Washington U. (Washington Post)