With state political contribution records, you can identify your prospect’s giving history to state-level candidates, which is a great indicator of capacity to give charitably. Plus, you can search by political party to identify donors who share an interest in your cause, and facilitate searches by contribution amount to identify high capacity donors.

National Institute on Money in Politics features one dataset:

  1. State Political Donations: Identify prospects who give to state-level candidates, political parties, lobby groups, and public officials with information including contribution year, range, and candidate information.