Why do Cons think that questions about Obama's underwear, turds, & toilets are funny?

It's both sides actually. To be critical in an intellectual sense, one actually has to know the facts, and most people (Liberal and Conservative) don't know the facts. As a result, they stoop to ad hominem and cheap invective. Whatever is being said about Obama today was also said by the other side a few years ago about G W Bush. It's not liberals vs conservatives, it's the knowledgeable vs, the unknowlegeable.