Methodology

How PartyLine Works

PartyLine turns official roll call data into clear, issue-level voting records with no commentary or spin.

How It Works

Three simple steps to find politicians who actually vote the way you think.

Share Your Views

Answer quick questions about where you stand on key issues like healthcare, climate, immigration, and more.

We Analyze the Records

We compare your positions against real congressional voting records for incumbents, and against clearly labeled estimated public-position data for challengers when no voting record exists.

See Your Matches

Discover which politicians vote the way you would, with issue-level breakdowns and key vote context.

Data Sources

For incumbents: VoteView for historical roll call votes, Congress.gov for legislation details, ProPublica, and the Bioguide directory for member metadata. For candidates: Ballotpedia, campaign websites, interest group ratings (e.g., NRA, LCV, ACLU), FEC donor data (DIME/CFscores), VoteSmart, and OpenStates.

How Votes Are Categorized

AI models analyze bill text, titles, and summaries to assign each vote to a primary issue category. This ensures legislation is grouped consistently across sessions.

Issue Scoring

Each incumbent issue score is calculated from categorized roll call votes using a significance-weighted averaging system. Landmark votes count more than minor votes, purely procedural votes are excluded from issue scoring, and the final score reflects long-run voting direction on that issue over time.

Scores range from 0 to 100. One end of the scale reflects one side of the debate; the other end reflects the opposite position. Scores in the middle reflect mixed voting behavior. Challenger scores are published separately as estimated positions sourced from campaign materials and Ballotpedia, with party baselines used only when evidence is limited. Each issue page describes what the two ends of the spectrum represent for that specific topic.

Update Cadence

Recent votes are ingested through a scheduled update pipeline, and the data freshness is tracked so new roll call votes can be added shortly after they occur.

AI Transparency

PartyLine uses artificial intelligence in two ways:

For incumbents: AI models classify the dominant policy issue of each piece of legislation so votes can be categorized consistently. Scores are derived from official roll call records. AI does not alter vote outcomes.

For candidates without voting records: AI models (Google Gemini) estimate issue positions from campaign websites, Ballotpedia profiles, endorsements, and other public sources. These estimates are clearly labeled and scored separately from vote-derived data.

Where AI-estimated positions can be verified against real evidence (interest group ratings, FEC data, VoteView records), the verified data takes precedence.

No Commentary. No Spin.

PartyLine is designed to organize voting data, not persuade. Every issue score is backed by public records and surfaced transparently.

Explore the Data

Explore the issue library to understand definitions and directional scoring, or take the survey to see your top matches.

Browse Issues