James Madison, “The Father of the Constitution” became a dual U.S. and French citizen having accepted French citizenship. I don’t think you’re going to find too many people who question the patriotism of the 4th President.
RC (DLC: Madison Papers); endorsed by TJ as received 6 June 1793 and so recorded in SJL. Enclosure: Madison to Jean Marie Roland de La Platière, French Minister of the Interior, April 1793, gratefully accepting the French citizenship conferred on him by the Legislative Assembly on 26 Aug. 1792, and avowing his wishes for the prosperity and glory of the French nation and the victory of liberty over the minds of its opponents (Dft in same; printed in Madison, Papers, xv, 4).
In recognition of their services to liberty, the Legislative Assembly in August 1792 bestowed French citizenship on three Americans, Madison, George Washington, and Alexander Hamilton—the last two of whom did not respond to the award—as well as on a number of European supporters of the French Revolution (Archives Parlementaires, 1st ser., xlix, 10).
http://founders.archives.gov/documents/Jefferson/01-26-02-0129
When did I ever say that acquiring dual citizenship would nullify your natural born citizenship? Strain, strain.. and there’s your gnat.