Recently the concept of presidential coattails has been used as an explanatory variable in analyses of congressional voting on presidentially sponsored legislation. This study pursues this line of inquiry by measuring the impact of presidential electoral strength, relative to that of congressmen in their districts, upon an index of presidential support. Regression techniques are used to depict how much presidential support increases for every electoral percentage point by which a president surpasses a congressman in the latter's district for members of the 83rd, 85th, 87th, 89th, 91st, and 93rd Congresses. Findings of this research show that congressional support of presidentially sponsored legislation increased between one and thirteen percentage points for every percentage point by which the president exceeded congressmen in the six elections analyzed. The impact of relative presidential electoral strength upon presidential support among congressmen of the president's party was stronger: (1) after landslide presidential victories rather than more competitive elections; (2) among non-Southern Democrats rather than Southern Democrats under Democratic administrations; and (3) in safe districts rather than more electorally competitive districts. Further, this relationship was stronger among Republican senators under Democratic administrations, and House Democrats under Republican administrations, than among the other partisan combinations.