A few quick historical thoughts here. Every time I turn on the television set I hear that American politics has reached an all-time low. Rubio is now talking about Donald Trump’s spray-tan and the pee in his pants. Trump is talking about Rubio’s apparent propensity for putting on makeup “with a trowel” and his infamous Poland Spring moment.
At one level, this is nothing new. This video about the Election of 1800 makes the rounds during presidential election cycles:
But as far as I know, these derogatory remarks were made by newspaper editors and supporters of the candidates, not the candidates themselves.