Sociopolitical events have been associated with shifts in youth mental health and attitudes. This study assessed six cohorts of American 12th graders (2012–2017) to examine trends in youths’ attitudes about themselves, the future, and others surrounding the U.S. 2016 presidential race and election. Analyses assessed overall trends and variation by political affiliation. Results indicated a rise across cohorts in future pessimism and nihilism after 2015, driven by youth identified as Democrat rather than Republican. A rise in concern for others was similarly driven by Democrat youth, whereas a rise in value of diversity was shared across all political identities. In contrast, Republican youth cohorts reported increasing external locus of control relative to their Democratic peers. Implications are discussed.