Until rather recently, the dominant paradigm in economics and other social sciences could be described as a wherein the legislative and regulatory initiatives of government were explained in terms of promoting the public's health and welfare. This perspective on government enterprise is in stark contrast to Adam Smith's views on the mercantilist policies of his day which included strong criticism of the monopolistic practices of the sovereign and economic groups seeking to utilize the power of the state to capture monopoly rents. The interest group as rehabilitated by Stigler [25], Landes and Posner [12], Peltzman [19], McCormick and Tollison [15; 16], Crain and Tollison [3; 4], and others, is closely related to Smith's perspective. From this perspective, these theorists have based their analyses on a positive theory which holds that the nature of government actions is determined by the costs and benefits faced by individuals brokering wealth transfers between groups. Following this tradition, we investigate the behavior of politicians as in markets for votes, campaign contributions, and public policies. The discipline of competition for votes, influence, ideas, money, and public policies in these markets requires that participants in the process bear some costs to enter and survive, let alone to prosper. Consequently, however one views the motives of public policy makers or the normative implications of the public goods they supply, the operative principle that the analysis below builds on is that survivorship of brokers in the process requires efficient supply behavior. The group theory is used in section II, below, to discuss efficient supply behavior for U.S. Senators and the testable implications of this behavior in markets for campaign funds and electoral support. Section III presents a series of econometric tests of the behavioral propositions derived from the group theory. Finally, section IV concludes the discussion.