Powerful New York Gov. Andrew Cuomo (D) today endorsed New York Rep. Charlie Rangel’s re-election bid,  the Empire State political blog Capital Tonight reports.

Rangel, facing a daunting Democratic primary challenge on Tuesday in the reconfigured 13th district, is seen by New York Democratic insiders as increasingly vulnerable as the result of a lackluster campaign.

There’s a growing sense among New York politicos that the 82-year-old Democratic icon, who was first elected in 1970, could well be unseated. His top competitor is ambitious state Sen. Adriano Espaillat, who, if elected, would become the first Dominican-American Congressman. Also on the ballot are Clyde Williams, a former national political director at the Democratic National Committee, retired business executive Joyce Johnson, and frequent candidate Craig Schley.

The winner of the Democratic primary is almost certain to be the winner of the general election in November, given the heavy Democratic lean of the Harlem-anchored district.