FiveThirtyEight’s Nate Silver today takes aim at some of the polls crying doom and gloom for House Democrats previously thought to be safe, cautioning that the volume of losses may not be as bad as some fear.
Many of the polls are either partisan-affiliated, or were “robopolls” that used automated scripts rather than live interviewers, or both. Polls with an explicit partisan affiliation are on average about 6 points friendlier to their candidate than those conducted by independent groups. Robopolls have not shown any persistent bias in the past — but this year, they have been 2 to 4 points more favorable to Republicans than traditional surveys, and the differences have tended to be larger in polls of House races as opposed to conducted in Senate or gubernatorial campaigns. So this is a group of polls that you’d expect to be pretty Republican-friendly.
Silver’s own calculations, some of what are shown in the chart above, predict that the GOP will gain 45-70 House seats. But by pretty much everybody’s numbers, the Democrats will lose their majority.