Face it fellas, conservatives are funny and liberals are desperate.
I don't know about you, but in all my experience, the mental images conjured up by George Bush trying to milk a stallion and Laura Bush identifying herself with a TV program about housewives who act like whores definitely meets the risque threshold. Granted, the author engages in hyperbole on the point about explaining the humor to his toddler, but let's not go overboard ourselves in the opposite direction.
All in good fun, yes, but much of the content of her bit showed questionable judgment.