Business Leagues
Requirements for exemption as a business league under Code section 501(c)(6), including the treatment of political campaign activities under that section.

Proxy Tax
Reporting and notice requirements for section 501(c)(4), (c)(5), and (c)(6) organizations that incur nondeductible lobbying and political expenses.

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.

Slide show - Rules for Exempt Organizations During an Election Year

Exempt Organizations Continuing Professional Education Text articles:

Political Campaign and Lobbying Activities of IRC 501(c)(4), (c)(5), and (c)(6) Organizations (2003)

Election Year Issues (2002)

Affiliations Among Political, Lobbying and Educational Organizations (2000)

Election Year Issues (1996)

Election Year Issues (1993)