The conclusion comes as a bit of a surprise, given that Democratic moderates have been assiduously targeting GOP-leaning suburbs as a prime opportunity for realignment in the age of Trump. To win back the House, the report argues, Democrats need to continue to make inroads in territory around booming metropolitan areas while also appealing to more culturally conservative Trump voters.

The paper spotlights some more uncomfortable realities: There were twice as many voters (around 6 million) who defected from President Obama to Trump than there were who went from Mitt Romney to Clinton (about 3 million). The GOP defectors disproportionately hail from states that aren’t competitive in Senate and presidential races, while the newfound Trump supporters are concentrated in the Midwestern battlegrounds. So Clinton’s impressive gains in deep-blue California’s Orange County and ruby-red Texas’s Harris County are unlikely to make a dent in the two states’ overwhelming partisan advantages.