Conventional political wisdom holds that rainy weather reduces turnout, and some say favors Republicans. But there's actually been some research done on this subject that might surprise you.

A few years ago, Dr. Steve Knack of the School of Public Affairs at American University published a paper called "Does Rain Help the Republicans? Theory and Evidence on Turnout and the Vote." According to Dr. Knack, this was the first time that the commonly circulated beliefs about the relationship between weather and elections had ever been rigorously tested.

For his national study, he analyzed standard election survey data, including both voters and non-voters, for three different years. He then looked at hourly rainfall data to determine how much rain, if any, fell during the times the polls were open. He then adjusted his results for other factors that affect voter turnout, such as age and level of education. Tomorrow night, after many of us have done our civic duty, rain or shine, I'll tell you what he found.