 However, as a result of the boycott the U.S. could no longer purchase metallurgical-grade chromium ore (a mineral needed for national defense) from Rhodesia, and was forced to import it from the Soviet Union—which, Lewis pointed out, had perfected a "no-man, no vote" system.Lewis was the author of legislation introduced by Sen. Harry F. Byrd Jr. (D-VA)in 1971 which provided that, in the event the U.S. was importing any strategically essential material from a communist source, there would be no prohibition against the importation of that same material from a non-communist source.After heated debate in the House and Senate, the measure - Section 503 of the Military Procurement Authorization Act of 1971 - was approved and, on November 7, 1971, signed into law by President Richard Nixon.