If you want to believe Biden is not fit for the presidency due to a deteriorating mind, there is plenty of evidence to support the theory. At times he has acted quite bizarrely on the campaign trail, telling voters to elect other candidates if they don’t like him as he is, and even insulting his critics – like when he jokingly called a woman questioning his poor Iowa performance “a lying dog-faced pony soldier.” At other times he has seemingly failed to remember basic things, like the name of President Obama or the wording of the Declaration of Independence.