When a committee (a person or group of people who receive or spend money for the purpose of influencing voters to support or oppose candidates) supports or opposes a candidate and raises at least $1 million, the committee must report its top 10 contributors to the California Fair Political Practices Commission (FPPC). The committee must update the top 10 list when there is any change.
These lists are available on the FPPC website at http://www.fppc.ca.gov/transparency/top-contributors.html.
To research campaign contributions for candidates, visit the Secretary of State's website at powersearch.sos.ca.gov.