Methodology
Swing
For each district we compute the two-party margin (Democratic share minus Republican share of the two-party vote) in the 2022 and 2024 general elections. Swing is the 2024 margin minus the 2022 margin, so a positive number means the district moved toward Democrats. Races without both major parties on the ballot have no margin and no swing. In states whose lines were redrawn between the two elections, the comparison is between different geographies and is flagged.
Who gave
Totals by source come from each principal campaign committee's FEC summary (Form 3). Donor-level detail comes from itemized receipts (Schedule A). Contributions of $200 or less in a cycle are usually not itemized, so they appear only in the small-donor total, not in donor lists. Donors are matched on normalized name plus ZIP code; this can split one person into two records but will not merge two different people.
How it was spent
Spending comes from itemized disbursements (Schedule B). Each payment is put into one category, first using the FEC's own purpose category and otherwise by keywords in the payment description. Memo entries are excluded so nothing is counted twice.
Outside money
Independent expenditures (Schedule E) by super PACs, party committees and other groups, for or against each general-election candidate. Spending against a candidate is credited as helping their opponent.
Sources
- Federal Election Commission, OpenFEC API and bulk data
- MIT Election Data and Science Lab, U.S. House 1976–2024
- U.S. Census Bureau, 119th Congress cartographic boundary files