see http://www.stat.columbia.edu/~cook/movabletype/archives/2009/02/no_no_noooooooo_1.html http://www.stat.columbia.edu/~cook/movabletype/archives/2009.... "on

see http://www.stat.columbia.edu/~cook/movabletype/archives/2009/02/no_no_noooooooo_1.html http://www.stat.columbia.edu/~cook/movabletype/archives/2009.... "one possibility is that the more serious candidates (the ones we know are going to win anyway) are more attractive. Maybe you have some goofy-looking people who decide to run in districts where they don't have a chance, whereas the politicians who really have a shot at being in congress take the time to get their hair cut, etc."