The following post by Ruy Teixeira, author of The Optimistic Leftist and other major works of political analysis, is cross-posted from his blog, The Optimistic Leftist:
Special elections provide important clues on political momentum. One under-analyzed area of special elections is state legislative seats. There are many more of these than there are of the heavily-publicized Congressional specials. Brian Stryker and Zac McCrary of ALG Research provide a detailed analysis of the legislative specials and detect very considerable Democratic momentum. Bottom line: the patterns are so strong that if they continue they could be enough to shift dominance of state legislature from Republicans to Democrats in 2018. That would be huge.
Caveats apply of course and Stryker/McCrary provide some at the end of their article. And Republican advantages from incumbency are considerable. Still, their results are rather striking and in an area where Democrats pay far too little attention.
Note this also about where Democrats should compete:
Additionally, many Beltway pundits continue to debate whether Democrats should target so-called blue-collar Obama-Trump type districts or more white-collar, suburban Romney-Clinton districts. The answer so far on the legislative level, is “Yes”; Democrats need not acquiesce to that false choice. Just like FiveThirtyEight, we find that Obama’s 2012 performance and Clinton’s 2016 performance in a district are equally predictive of 2017 results….
Because both 2012 and 2016 have been equally important predictors, a lean Obama district that swung heavily to Trump is just as ripe an opportunity as a strongly Romney district that shifted to Clinton. Republican legislators who hold either of those types of districts — as well as a much broader swath of GOP districts — should be very worried by what has occurred at the legislative level over the past several months. Likewise, Democrats do not necessarily need to choose between targeting state houses in places like Iowa where Trump did well in 2016 or states like Arizona or Virginia, where Trump is generally weaker than other recent Republicans.