The
Primary Colors scoring system is useful for identifying which Democrats to challenge in a primary, but it’s also useful for holding members of Congress accountable in seats too risky to support a left primary challenge.
Let's take the extreme example of West Virginia. Joe Manchin is never going to be anyone's favorite Democrat, but you'd be crazy to primary Joe Manchin. The state's PVI is R+13, and yet it's held by two Democrats. We are very lucky to have any Democrat in this seat, let alone two.
But while we definitely wouldn't want to primary Joe Manchin, we do want to anchor his expectations of how far right he's allowed to go. Lawmakers tend to overestimate how conservative their constituents are, so the simple act of giving them information about where the limits roughly are can prevent them from overshooting to the right.
Our algorithm thinks, based on the actual behavior of his Senate colleagues, that Joe Manchin can get away with voting with progressives about 77.8% of the time, but he's actually only with us 66.1% of the time.
Representing the same electorate, John Rockefeller votes with progressives 92.3% of the time.
Now John Rockefeller, who's retiring this year, is obviously in a much different spot than Manchin. West Virginia wasn't always this conservative, and Rockefeller's been in the Senate since 1985. So a key reason he can vote like this is that he's been in the Senate since 1985, and absent some major scandal, that kind of successful incumbency nearly makes you untouchable. Rockefeller's built up a ton of credibility with voters over time, he's on key committees, and so on.
Manchin can't get away with voting with progressives at Rockefeller's 92.3% rate as a freshman Senator in a conservative-trending state.
But if we can push him up to the 77.8% rate that the Primary Colors algorithm says he can safely do, that'd still be a significant shift to the left in the Senate's center of gravity.