What are the partisan leanings and Cook PVI ratings for each Massachusetts congressional district in 2025?

1. What Cook PVI is and how the 2025 values were calculated

The Cook Partisan Voting Index reports how each congressional district performed at the presidential level relative to the nation; a label such as D+2 means the district voted two points more Democratic than the country did on average in the examined cycles (Cook’s definition) ^[1]. The 2025 PVI values use the combined 2020 and 2024 presidential election results, with updated allocations for 2020 results to reflect post‑2020 redistricting; Cook worked with Dave Leip’s Atlas to disaggregate precinct and split‑county votes for 2024 and to allocate split precincts for 2020 as needed ^[2].

2. Where to find the 2025 PVI numbers for Massachusetts’s districts

Cook’s 2025 district map and list contain PVI scores for all 435 districts and are the authoritative source for district‑level ratings ^[1]. The Cook PVI overview and the specific 2025 PVI page describe the dataset and methodology and state that the full list of 2025 PVIs is available on Cook’s site ^{[2] [3]}. The specific numeric PVIs for Massachusetts’s 1st through 9th (or however many districts Massachusetts had in 2025) must be read directly from Cook’s published district list ^{[1] [3]}.

3. What the PVI numbers mean for partisan lean in Massachusetts

In general, a “D+N” PVI indicates the district leans Democratic by N points versus the national presidential two‑party vote; “R+N” indicates an equivalent Republican lean; an EVEN rating means performance was within half a point of the national average (Cook’s explanatory text) ^[1]. Cook’s PVI is a structural measure of presidential leaning rather than a short‑term race rating; Cook distinguishes PVI (longer‑term partisan baseline) from its race ratings (which project who will likely win upcoming elections) ^[2].

4. Limitations and reporting caveats you must consider

Cook’s 2025 PVI relies on disaggregated precinct and census‑block estimates where ballots crossed district lines and on proportional assignments for some unallocated votes; that introduces estimation error in certain split‑precinct areas and was explicitly acknowledged by Cook and Dave Leip’s Atlas as part of the methodology ^[2]. The PVI measures presidential performance only and does not directly translate to House outcomes where incumbency, candidate quality, turnout, and local issues matter; Cook itself separates PVI from its race ratings for that reason ^[2].

5. Alternative or secondary sources and context

Secondary summaries of PVI history and interpretation are available (for example Ballotpedia’s explanation of Cook PVI and the long‑standing use of the metric), but the most current numeric 2025 district PVIs are published by Cook and its 2025 district list is the primary reference ^{[4] [1]}. Wikipedia and other aggregators note the 2025 PVI release and general findings about national district polarization but reproduce Cook’s underlying numbers from the same primary Cook dataset ^[5].

6. Practical next steps to get the district‑by‑district ratings

To obtain the exact 2025 Cook PVI rating for each Massachusetts congressional district, consult the Cook 2025 district map and list page where the 435 district PVIs are listed; Cook’s dedicated PVI pages also explain methodology and definitions that clarify interpretation ^{[1] [2]}. Available sources do not include a transcribed Massachusetts‑only PVI table in the provided results, so cite Cook’s district list directly for precise numeric values ^{[1] [3]}.

Limitations: this report uses only the provided Cook and explanatory materials; available sources do not list the individual Massachusetts numeric PVIs in the material supplied here, so I direct you to Cook’s 2025 district list for the exact per‑district numbers ^{[1] [2]}.