Whether these statistics are an accurate measure of a president’s ability to help congressional candidates within his (someday her) party is, in my view, somewhat debatable. Running ahead of congressional candidates may be the sign of the president’s electoral strength, but it also might indicate weaker performances by the congressmen and women in those districts. Consider this hypothetical: in two successive elections, a presidential candidate wins 55% of the vote in a particular district. In the same district, a congressman wins 57% of the vote in the first election and 52% in the second. According to the statistic measured above, the presidential candidates “coattails” would have increased by one from the first election to the second, even though support actually declined for the congressional candidate. Particularly since split-ballots are becoming more and more prevalent, I suspect that the hypothetical situation I’ve described is a reality in many districts across the country.

If that is in fact the case, it may speak to the fact that most presidents actually benefit from a certain degree of sustained support throughout their years in office. Indeed, administrations elected during a change of party rule have generally been reelected to a second term (Carter is the only exception in the post FDR era, and there are many ways in which his Presidency was exceptional). It would be interesting to look at the historical trends for congressional elections in the second, fourth, and sixth years of presidential administrations to see if congressional candidates of the same party garner greater or lesser shares of the vote and how these levels of support compare to those of the president.

If it is true that presidents running for reelection help improve the performances of congressional candidates, then it may suggest that peak of presidential influence might occur in the third and fourth years of the administration because this is when down-ticket candidates would benefit most from allying with the president. After the second election, though, a reelected president may have less to offer potential supporters in congress, and his power prospects may wain accordingly.

In any case, I’m very interested in this and other ways of trying to measure the influence of the president on members of congress. Perhaps fundraising – either for the candidate or for the congressional campaign funds – is also a good indicator of a president’s ability to inspire electoral victories.

Thanks for the post!