This paper utilizes new data to evaluate the determinants of the political influence of thirty‐five manufacturing industries on the U.S. Congress during 1976–80. Several measures of influence serve to distinguish between political activity and success. Seller concentration and geopolitical dispersion increase both activity and success, but neither industry size nor leading‐firm size proves significant. We test whether political expenditures facilitate obtaining the favors conferred on an industry by its market structure or by influence independent of that strurture; statistical inference strongly confirms both