Bryan H. Wildenthal (Thomas Jefferson School of Law) has posted Memorandum on Supreme Court Vacancies and Confirmations During Presidential Election Years on SSRN. Here is the abstract:
The author summarizes historical examples of Supreme Court vacancies which occurred during presidential election years, or during the year prior to an election year, or during the final part of a president's term after the election year but before the beginning of the next presidential term. The memorandum summarizes the outcomes of presidential nominations to those Supreme Court vacancies.
There is not a single case in American history in which a president chose not to make a Supreme Court nomination in such circumstances, even for vacancies occurring extremely late during (or even after) the election year. Of the total of 26 such vacancies considered, the Senate gave full consideration to nominees in at least 23 cases (88%), and 22 (85%) of the vacancies were successfully filled by the incumbent president.
Two of the 26 cases, when an incumbent president made a nomination after being reelected (to fill very late vacancies), are best excluded as not relevant on the whole. Of the remaining total of 24 relevant vacancies considered---15 occurring during the election year (or even in the early part of the year following), and 9 occurring during the year before the election year but persisting into the election year---at least 21 (87.5%) received Senate consideration and 20 (83%) were successful.
Further excluding seven vacancies which occurred after June during the election year (thus much closer to the election and allowing much less time for considering any nominee), 15 of the 17 remaining vacancies (88%) were successfully filled by the incumbent president, and all but one case (94%) received full Senate consideration.
In the one solitary case (April 1844) of an early-election-year vacancy that did not receive a full Senate vote, however, there were actually two vacancies pending that year, and that lame-duck president did obtain at least two final Senate votes on, and eventually succeeded in filling, the other vacancy that existed that year, which occurred in December right before the election year. So the Senate actually gave consideration to at least one nominee in 100% of the years in question. If the 1968 announced retirement (without any actual vacancy) is added to the group of 17, then the rate of at least substantial Senate consideration remains at least 94% (or 100% depending on how one interprets 1844), and 15 of 18 cases (83%) resulted in successful replacements by the incumbent president.
The most highly relevant examples to compare with the current situation involving President Obama and the vacancy created by Justice Scalia's death on February 13, 2016, would be the eight vacancies that actually occurred during a presidential election year, but still early enough (no later than June) to allow ample time for considering any replacement. Again, the president made a nomination in all eight cases (100%). Of those vacancies, at least seven of eight (87.5%, or 100% if one credits 1844) received full Senate consideration and six of eight (75%) were successful.
