The ranking Democrat on the House Foreign Affairs Committee said the national security adviser may have violated laws barring the conduct of foreign affairs without government sanction.
Igor Sadikov, a BDS activist and member of the student union council, cited his Jewish origins in dismissing allegations that his tweet was anti-Semitic.
An organization representing Italian Jewry protested the ruling, which traced the labeling of fans of Rome's Catania team as Jews to a sporting rivalry rather than racial prejudice.
