Paid political advertisement:
Scott Mann's letter includes a link to the California Legislative Information website, which spells out the obligations of candidates to:
-- Campaign fairly and openly.
-- Not permit the defamation of other candidates.
-- Not permit negative prejudice of any kind.
-- Not permit unethical practices in one's campaign.
-- Not coerce election help or contributions.
-- Repudiate support from those who don't adhere to these practices.
-- Defend and uphold and right of every qualified American voter to full and equal participation in the electoral process.
The full document is listed here.