Cook PVI

The Cook Partisan Voting Index measures how strongly a congressional district leans toward one party compared to the nation as a whole. A district scored R+6 voted Republican by six points more than the national average across the last two presidential elections.

Cook PVI is a baseline, not a forecast. A district can have an R+6 PVI and still elect a Democrat — incumbency, recruitment, fundraising, and the national environment can all override district lean. Thin Gold uses PVI as one input among many when rating races; we never let it be the only one.

The index updates after each presidential election. The current values are based on 2020 and 2024 results. Cook Political Report publishes the full district list annually.