The second issue would be vetting the prospective candidate to see if he carried the loyalty of his former country interests over that of the United States. I can see where this could fairly be called a toss-up with our present political system of selecting only those interested in their own and special interests instead of genuine regard for the betterment of the nation as a whole.
The biggest problem I see, would be the possibility of electing a succesor to the policies of the Third Reich or the Soviet Union. We have enough of our own extemists, thank you!