Warren’s performance in 2018 was one of the weakest for a Democratic Senate candidate. I created a simple statistical formula explaining the results of the 34 Senate races with at least one Democrat (or independent who caucuses with the Democrats) and one Republican. Controlling for a state’s weighted average partisanship and incumbency, Warren’s performance was the sixth worst of all Democrats. She did 7 points worse than expected. (For comparison, Minnesota Sen. Amy Klobuchar and Vermont Sen. Bernie Sanders outperformed their baselines by 9 and 12 points respectively.)
It’s not the only bad number for Warren published this week. A UMass/YouGov study of Massachusetts Democrats and Democratic-leaning independents finds former Vice President Joe Biden at 19% to Sanders’ 14% to Warren’s 11% in a hypothetical Democratic presidential primary. A large 27% answered “don’t know.” YouGov’s polling does not meet CNN’s standards because it doesn’t use probability sampling.