How the Bipartisanship Score is calculated

The Bipartisanship Score shows how often a member of Congress votes the same way as most members of the other major party.

Which votes count

• We use the member's most recent recorded roll-call votes in their chamber (House or Senate), up to 30 qualifying votes.
• Only votes where the member voted yea or nay count. Absences, "not voting" and "present" are left out.
• For each vote we find the majority position (yea or nay) of the other major party's members. Independents are not counted in either party's majority.
• Votes where the other party split evenly, or where none of its members voted yea or nay, are left out.

The formula

p is the share of qualifying votes where the member voted the same way as the other party's majority.

Score = 1 + 9 × p, rounded to the nearest whole number.

A score of 10 means the member always voted with the other party's majority. A score of 1 means they never did. Pages label 8–10 "Bipartisan", 4–7 "Moderate" and 1–3 "Partisan". These labels describe voting patterns only; a higher or lower score is not a judgment of the member. Member pages show the raw count, for example "13 of 27".

Who gets a score

• Members with fewer than 10 qualifying votes are not scored.
• Independents who caucus with a party (currently Sen. Bernie Sanders and Sen. Angus King, who caucus with Democrats) are compared against the other party (Republicans). Other independents are not scored.

Data and limits

Data comes from official House Clerk and U.S. Senate roll-call records. Scores update as new votes are recorded (cached for up to 6 hours). The score counts all roll calls equally, including procedural votes and nominations, and does not judge whether any vote was right or wrong. It is a mathematical summary of the public record, not an endorsement or rating of any member.

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