From Home Base to Swing States: The Evolution of Digital Advertising Strategies during the 2020 US Presidential Primary.

Political advertising on digital platforms has grown dramatically in recent years as campaigns embrace new ways of targeting supporters and potential voters. We examine how political campaign dynamics have evolved in response to the growth of digital media by analyzing the advertising strategies of US presidential election campaigns during the 2020 primary cycle. To identify geographic and temporal trends, we employ regression analyses of campaign spending across nearly 600,000 advertisements published on Facebook. We show that campaigns employed a new strategy of targeting voters in candidates' home states during the "invisible primary." In contrast to earlier studies, we find that home state targeting is a key strategy for all campaigns, rather than just for politicians with existing political and financial networks. While all candidates advertised to their home state, those who dropped out during the invisible primary tended to spend disproportionately more than the candidates who outlasted them. We also find that as the first wave of state caucuses and primary elections approach, campaigns shift digital ad expenditures to states with early primaries such as Iowa and New Hampshire and, to a lesser extent, swing states. [ABSTRACT FROM AUTHOR]