"I think of it as an awesome responsibility," he said.
Andrew Gelman, a professor of statistics and political science at Columbia University, was co-author of a study before the 2008 presidential election that found that, on average, a voter had a 1 in 60 million chance of deciding that race.
The Electoral College means the odds vary by state. This year's chances range from roughly 1 in a million (for a voter in the battleground state of Ohio) to essentially zero (in states such as vastly Republican Wyoming or deeply Democratic Vermont).
Gelman's numbers might seem to validate the inertia of the 4 in 10 eligible adults who don't bother to vote even in presidential years. Yet, Gelman is a voter. "Part of our role as citizens is to vote," he said.
Image: Rep. Paul Ryan and his wife Janna, right, answer questions from local and region press organizations after voting at the Hedberg Public Library in Janesville, Wis., on election day, Tuesday, Nov. 6, 2012