You are building a campaign’s voter file under European data law. Four guesses about what you may keep, and what the courts have actually punished.
From the article’s sources: Regulation (EU) 2016/679; Verwaltungsgerichtshof (2026); Bundesverwaltungsgericht (2024a, 2024b). Names and scores in the file are invented. Pixel art drawn in code. Not legal advice.