Voter turnout in congressional elections tends to be lower than that in presidential elections.
On average, congressional voter turnout in presidential election years is about 4.1% lower than
presidential voter turnout, the result of a phenomenon known as "ballot roll-off"
In midterm elections, congressional voter turnout drops of signicantly, averaging a decline
of about 13%.
Source:
U.S. Bureau of the Census. Statistical Abstracts of the United States, 2004-05, Table No. 409.
2004 estimates based on report by Center for the Study of the American Electorate, 1/14/2005
