Renewed scholarly interest in the role of US congressional parties has recently coincided with a continuing interest in legislative committee influence and the extent to which that influence relies on committee preference composition. We argue that majority party incentives to influence composition vary by committee salience and party margins. In turn, the party’s ability to influence composition of salient committees is constrained, but varies by party resource levels. We present data on committee composition for the 80th to 104th US Houses and test these expectations using time-series cross-section analysis. The evidence provides support for the predictions – which have been hypothesized or tested anecdotally but have not heretofore been systematically tested – explaining both spatial and temporal variation.