Mickey Mouse voter

Why would a voter go to the trouble of going to the polls, taking a ballot, and unambiguously marking only one race? Sure, it's the Presidential race, and 2008 was a very important election, but this numbskull voter wrote in Mickey Mouse. There is a small mark in Al Franken's oval, but since this non-voter (as it turns out) inked Mickey's oval very well, I can't count the faint mark as a vote for Franken.