It is well established that various characteristics of a congressional committee may shape and, to an extent, standardize its handling of a range of policy areas. This article, however, examines the substantial variations that most committees continue to display as they move from issue to issue. Why is it that the House Commerce Committee, for example, approaches issues like major-disease research, health care delivery, cable television development, and power plant siting in such radically different ways? What determines the incentives of legislators to invest time and effort in a policy area, and to orient themselves toward broad “public” interests, once involved? Focusing on the House and Senate Commerce Committees, the article takes as its data base patterns of legislative action and inaction in major areas of the committees' jurisdiction during 1969–1974. Particular attention is given to how perceived levels of group conflict and of public salience affect a legislator's orientation toward a policy area, and to the level and direction of executive involvement as an intervening variable of major significance. High-salience, low-conflict areas (e.g., health research) generally offer the strongest incentives to congressional involvement, and low-salience, high-conflict areas (e.g., communications regulation) the weakest, while mixed cases (e.g., a high-salience, high-conflict area like health care delivery) display considerable variability. Issues may change considerably with time in their perceived levels of salience and conflict, and legislators can influence, as well as respond to, such changes. Congressional initiatives often respond to perceived “neglect” on the part of the executive, or disagreement with the content of its moves. But particularly in high-conflict areas, congressional activists will often find that their success requires executive involvement.