In my book, The Great Alignment: Race, Party Transformation and the Rise of Donald Trump, I argue that the United States has entered a new era of electoral competition in the 21st century. The most important characteristics of 21st century elections are partisan polarization and nationalized elections, and the results of the 2018 House elections provide striking evidence of both. The outcomes of House contests in 2018 were overwhelmingly determined by two factors — the partisan composition of House districts and the unpopularity of President Trump in many of those districts, including some that had supported him in 2016. …
An important implication of these results is that the voting records of House incumbents may have had far less impact on their reelection chances than in the past. Even when members tried to appeal to voters from the opposing party by moving to the center of the ideological spectrum, they may have received little electoral benefit. CONT.
Alan I. Abramowitz (Emory), Sabato’s Crystal Ball