Center for Study of the Presidency: Devoted to the study of the American Presidency, historical and current information on the president and the presidency along with political and government links
LII Supreme Court Decision: Presidency: Case law dealing with the issues of the presidency.
MultiEducator History of Presidential Elections: Provide graphs on both Electoral votes and popular for all US Presidential Elections.
What Does High Crimes and Misdemeamers Mean?: An examination of the meaning of the language that is used to define the impeachment process. From the conservative Claremont Institute.