Rush Limbaugh is still pumping Birtherism, hyping on his show today an essay in National Review by Andrew McCarthy, who dissented in part from the magazine's official editorial against the movement:

In that article, McCarthy falsely stated that the matter of Obama's Kenyan father, which would present "dual-citizenship issues," was "an uncharted constitutional concept." In the audio clip above, Limbaugh also promoted the dual-citizenship claim.

In fact, this territory is quite well charted. President Chester A. Arthur, who was elected Vice President in 1880 and then served nearly a full term after President James Garfield's assassination, was born of an American mother and an Irish immigrant father who was not yet a citizen at the time Chester was born. Arthur was also born on U.S. soil (Vermont), but faced rumors from political opponents that he'd been born across the border in Canada. This is essentially the exact same set of circumstances as in Obama's case.

On the other hand, there is one rather obvious difference between Obama and Arthur. And for Limbaugh and the Birther movement, perhaps this does make for an important distinction.