2008 is not the year to elect someone named Willard as President of the United States. We have already had a Millard (even though he wasn't elected*) and I think that is close enough to Willard as we need to go.
Rudy? Sounds like a movie to me.
Duncan Hunter? No, two last names.
Ron Paul? Two first names.
*Millard fillmore succeeded Zachary Taylor who died of acute gastroenteritis.