Eugene Mazo has posted this draft on SSRN. Here is the abstract:

Why do we have an Election Day but not a Primary Day? No aspect of the presidential nomination process causes as much controversy as the primary calendar. The calendar starts off in January or February and ends in June of each election year. A total of 57 jurisdictions hold their primaries and caucuses over the course of these months. The Iowa caucuses always start off the calendar, followed by the New Hampshire primaries. The results of these contests invariably eliminate some candidates while they bestow momentum on others. More candidates participate in the first few nomination contests than in the last ones. Disproportionate power is thus given to voters whose states hold early nomination contests, while the citizens of states with later primaries are provided with less or sometimes no voice in choosing their party’s presidential nominee. In some years, a party’s presidential nomination contest has ended before citizens in late-voting states have even had a chance to cast their ballots. To gain more influence and a greater voice, states have consistently attempted to move their primaries forward in a process that has come to be known as “front-loading.” The dynamic repeatedly leads to calls for reform, as politicians, journalists, scholars, and citizens all try to rethink the primary calendar.

This chapter examines the primary calendar and what can be done to change it. It begins by explaining why Iowa and New Hampshire always hold their nomination contests first, as well as how other states have tried to match their power through front-loading. The chapter then briefly looks at the 2020 primary calendar. It then turns to examine the one reform that a majority of voters consistently support: holding all primaries and caucuses on a single day. Scheduling a national Primary Day is important not only because the current staggered nature of the calendar privileges some candidates over others, but also because it favors voters and party members in some states over those in other states. The way to remedy this problem and to ensure all voters are treated equally is to hold our 57 nomination contests on the single day.

While scheduling a national Primary Day would appear to be a simple, direct, and fair way of selecting a party’s presidential nominee, a national primary also comes with its own challenges. A national primary would change the nature of presidential campaigns by shifting the resources and spending of candidates from low-population states like Iowa, New Hampshire, and South Carolina to high-population states like California, Texas, and Florida. It would also diminish the aspirations of candidates with less money and name recognition by denying them the opportunity to build momentum in the early states. A related concern has to do with how the votes would be tallied and added in a national primary when the list of candidates running in the 57 different primaries and caucuses could potentially be very large, as well as what should happen if no single candidate manages to wins a majority of these votes. Finally, there is the thorny issue of how a single primary date could ever be imposed on the states. Whether Congress has the power to set the date on which the states hold their primaries is a constitutional question that remains unresolved. Whether the national parties would ever have the willpower to impose a national primary also remains in doubt. As a result, while the benefits of a national Primary Day may be substantial, the path to getting there comes with its own challenges.