Tax Information for Political Organizations: Resources for political organizations exempt under Code section 527, including political action committees affiliated with section 501(c) tax-exempt organizations. Attempts to Influence Judicial Appointments: An article describing the tax treatment of attempts by exempt organizations to influence judicial appointments. Common Tax Law Restrictions on Activities of Exempt Organizations: A chart comparing seven federal tax law attributes of five common types of tax-exempt organizations, including the extent to which they engage in political activity. Revenue Ruling 2004-6, 2004-4 I.R.B. 328 PDF: Clarifying the tax implications of political activities by section 501(c)(4) social welfare organizations.