You may as well judge a candidate by how he dresses or whether or not you like his hair style.
Since the TV era, isn't this more or less what's been happening? We've been electing attractive presidents, and presidents with good images: Kennedy, Clinton, Reagan (though not at his peak when he was elected), and, well, Bush the Younger (as much as it pains me to admit it, he's pretty handsome.) Shame on all of us, but it does influence our decision.