When considering electoral campaigns, candidates receiving contributions from relatively unpopular industries should be regarded less favorably by voters that have information on the sources of funding. To offset this unpopularity effect, politicians may either demand more money for campaign advertising from these industries in order to persuade less informed voters, or shy away from unpopular contributors to avoid losing the support of the informed electorate. Our model predicts that the first effect dominates, and electoral contributions are increasing in industry unpopularity. By using U.S. House elections data and different identification strategies, we provide robust evidence in favor of our predictions. (JEL D72, P16)