The more time you spend looking at the battlegrounds in each chamber, however, the more you’ll come to two important conclusions:
The House and Senate battlegrounds really aren’t that much alike. In several important respects, in fact, they’re almost opposite from one another. For example, House battlegrounds are more educated than the country overall, while Senate ones are less so.
The Democrats’ map in the House is fairly robust, because they aren’t overly reliant on any one type of district. (This stands in contrast to the Senate, where most of the battlegrounds fit into a certain typology: red and rural). While House battlegrounds are somewhat whiter, more suburban and more educated than the country overall, there are quite a few exceptions — enough so that Democrats could underperform in certain types of districts but still have reasonably good chances to win the House. This differs from Hillary Clinton’s position in the Electoral College in 2016, in which underperformance among just one group of voters in one region — white working-class voters in the Midwest — was enough to cost her the election.