Just when you thought you could escape politics, even briefly, in our fair city, there’s a new menace lurking: the subversive marketing of yet another set of political trading cards. It happened on Monday, when exiting the Dupont Metro. The perfect storm of heels, gum and litter had left me with a little present. Further inspection revealed it to be a small piece of cardboard with an illustration of George W. Bush, surrounded by flames…