Does media influence operate primarily on low-information swing voters, or can it also affect party activists who shape intraparty ideological factions? We examine Fox News’ role in the rise of the Tea Party movement within the Republican Party, leveraging differences in its channel positions across cable systems to isolate exogenous variation in exposure to the channel (Martin and Yurukoglu, 2017). In early 2009, Fox News did not noticeably boost Tea Party rally sizes. But later in the 2009–2010 cycle, exposure to the channel significantly increased campaign fundraising and primary election vote shares for Tea Party candidates compared to other Republican candidates. These findings dovetail with content analysis demonstrating pro-Tea Party slant on Fox News that emerged only in 2010. The Tea Party movement benefited from the backing of a powerful media outlet–a rare advantage among insurgent movements–which enabled it to rapidly move from the fringe to the center of the Republican Party.
Li et al. (2026) studied this question.