The present inquiry focuses upon recent levels and trends of public support and nonsupport of the U.S. Congress. The data are drawn from statewide surveys of Wisconsin adults in 1970–1978 and from such sources as CPS/NES, Gallup, and Harris. Measurement focuses upon four major types of public support for Congress—pure specific support (performance), pure diffuse support (including general confidence in the institution, sense of personal efficacy in relation to Congress, desire for institutional reform or maintenance and the amount of power preferred for Congress relative to other branches), and two mixed types of support, long-term performance assessments and confidence in congressional incumbents. With few exceptions, Congress has suffered a general erosion of public support over the past decade on most indicators.