Presidential and Congressional elections have enormous consequences. Political parties are the institutional actors that contest and win almost every state and federal election. The present and past development of the US party system and how the parties have contested elections is the focus of this course, especially the partieschanging ideologies, personalities, and geographic variation over time, up through and including the elections of 2020. Students learn about theoretical views of political parties, the electoral rules that produce party incentives and structures, and key moments in the development of the US political party system. We also focus on the 2020 election campaign, including not only the presidential contest, but also House and Senate races.