Imagine a three way race for president with only New York politicians in the running. Oh, the humanity.

But Michael Bloomberg’s announcement that he is shedding his Republican registration as a possible prelude to an independent run for president raises the admittedly unlikely specter of the country having to choose among a third party New York mayor, a Republican former New York mayor and a Democratic New York senator. Somewhere Franklin Roosevelt is smiling and Al Smith and Tom Dewey are having a good cry.

With the possible exception of Northern New Jersey, this presidential version of a Subway Series would not be expected to play particularly well in an estimated 48 and a half states. So expect to see at least one of the candidates try to convince voters they’ve lived a life outside the Empire State.

We can see Hillary Clinton return to her suburban Illinois roots and reemphasize her devotion to the Deep South. She’ll turn up at the Chicago Cubs’ spring training camp soon after the Iowa caucus, followed by a side trip to Little Rock and a place called Hope. More will be made of her nativity in Chicago, growing up in Park Ridge and even going to college in Massachusetts and law school in Connecticut. Living in Arkansas for 17 years will no longer be considered a flaw.

Letting voters know you’ve had a life beyond the five boroughs would be more difficult for Boston-born Bloomberg. He can recall a happy youth in Brookline and Medford and college at Johns Hopkins in Baltimore and Harvard, but his money and his political career are all New York.

Rudy Giuliani won’t even try. Born in Brooklyn, he grew up in Garden City South on Long Island, returned to Brooklyn for high school, moved all the way to the Bronx to attend Manhattan College and on then on to Manhattan for NYU Law School. His triumphs as a prosecutor were all east of the Hudson. And there’s not much political capital to be gained from pointing out that your third wife comes from Pennsylvania.