Ben Smith has a great catch – the North Dakota Republican Party fronting its website with a joke about the White House party crashers demanding President Obama’s birth certificate. The news here is the steady mainstream Republican acceptance of a deeply nutty and quasi-treasonous conspiracy theory about whether the president of the United States is really an American citizen. Yes, it’s just a joke here. But when’s the last time a Democratic Party web site fronted a joke about, say, whether Sarah Palin is the real mother of Trig Palin? (She is, by the way.)