Presidential coattails are frequently addressed in American politics, but we know little about their impact on the outcomes in elections for the House. Yet it is here that they are most significant. If presidential coattails do affect congressional elections, they can be the cause of increased support for the president (from new representatives of his party) and increased support for policy change (from representatives of a new generation). This research examines the relationship between how well a president runs in a congressional district and the success of the congressional candidate of his party in winning the district. The analysis is done for each of the six presidential elections from 1952 through 1972, and is done separately for the North and South as well as for the country as a whole. In every instance, constituency party strength is controlled in order to isolate the impact of the presidential candidate on the congressional outcome. The basic conclusions are that presidential coattails have had a declining impact on the outcomes in congressional elections since 1952 and that in recent elections their impact has declined to the vanishing point. This, it is argued, is primarily due to the increasing lack of competitiveness of congressional districts.