Ned Foley has posted this timely draft on SSRN. Here is the abstract:

In the wake of President Trump’s acquittal in the Senate impeachment trial, the United States will need to hold a presidential election in unprecedented circumstances. Never before has an incumbent president run for reelection after the opposing party in Congress has declared that the fairness of the election cannot be “assured” as long as the incumbent is permitted on the ballot. This uniquely acute challenge to holding an election that the public will accept as valid follows other stresses to electoral legitimacy unseen before 2016. The Russian attack on the election that year caused Americans to question their capacity to hold free and fair elections in a way that Americans had not questioned previously.

Given these challenges, this essay tackles the basic concept of what it means for the outcome of an election to be valid. It turns out that, because of the way American history has unfolded, this basic concept is contested now although it had been settled previously. Current circumstances require renewing a shared conception of electoral validity. Otherwise, participants in electoral competition—winners and losers alike—cannot know whether or not the result qualifies as authentically democratic. Accordingly, after reviewing the history that has led to the present difficulties, this essay offers a renewed conception of electoral validity and both explains the theoretical basis for this renewed conception and then applies it to some of the most salient threats to electoral validity that are foreseeable in this year’s and future elections.

In brief, the proposed standard of electoral validity distinguishes sharply between (1) direct attacks on the electoral process that negate voter choice and (2) indirect attacks that improperly manipulate voter choice. Direct attacks undermine electoral validity, whereas indirect attacks do not. It is essential, however, that the category of direct attacks encompasses the disenfranchisement of eligible voters, which prevents them from casting a ballot, as well as the falsification of votes reported in the tallies of counted ballots.