Serious voters, one would hope, want campaign 2012 to be about serious things: health care, foreign policy, civil rights, jobs, climate change, the budget deficit, education, that sort of thing. Filmmaker Joss Whedon, a Barack Obama supporter, wants to add the zombie apocalypse to that list. In a new (satirical?) YouTube video, he warns that a vote for Mitt Romney could bring on a supernatural disaster for mankind.

In the video, Whedon, the creator of "Buffy the Vampire Slayer" and the director of "The Avengers," declares...