Actually, if any individual garners a certain write in vote percentage of the overall vote, the write in votes must be counted. In Alaska, recently, a write in candidate for governor got more than the official standard bearer of the Republican party.One reason, I suppose, that not much attention is given to those votes normally is that you come across some real oddities. We've seen votes for, among others, Mickey Mouse, Donald Trump, and Pac Man.
Ebbie