This would mean, unless corrected by a modification of the 14th Amendment, that no freedman/woman or child of a freedman and or freedwoman could EVER become a U.S. citizen by birth, to this day. It means that no American Indian could EVER become a natural born American (which is sort of bad, considering we stole the place from them). It means that no person descended from those living in the Louisiana Purchase at the time of acquisition, in the areas acquired at the admission of Texas, and living in the territory gained at bayonet point from Mexico, in Hawaii, Puerto Rico, etc.Clear definition of Natural born citizen...impact depends on definition. Most restrictive would be born on US soil of two American citizen parents. This hits Obama, Cruz. Mc Cain, George Romney and perhaps others. Impact is all in the definition.
It would disenfranchise anywhere between 1/3 and 1/2 of the U.S. population.
In all likelihood it would result in, at best, a second revolution, and at worst the dissolution of the U.S. possibly as early as 1830, almost certainly by 1880. It would make the United States into a Western Hemisphere version of Sparta, with a tiny native population and a mass of helots.