As of 2015, 36 states and the District of Columbia allow any registered citizen to cast a vote before Election Day through the mail or at designated locations (National Conference of State Legislatures 2015). Early voting programs have become a significant feature of American elections. In both 2008 and 2012, more than 30% of the electorate cast ballots before Election Day, including a majority of voters in at least nine states in 2012 (Demos 2014; McDonald 2012). Numerous surveys indicate that voters appreciate the convenience offered by early voting (Kasler 2014; Martens 2014; Warner 2013). Some voters also recognize that voting before Election Day means an early end to the barrage of mailings, phone calls, and canvassing visits directed by parties and candidates (Benac 2010). States offering early voting do so not only in general elections, but in primary contests as well. While national figures are difficult to obtain, a substantial number of voters cast early ballots during both the 2008 and 2012 presidential nomination cycles. In fact, a majority of primary voters participated early in California and Texas in both 2008 and 2012 (Austin Community College 2010, 6; California Secretary of State 2012; Reynolds 2014). (1) Early voting has become significant enough in presidential primaries that exit pollsters now routinely conduct telephone surveys of early voters to supplement their primary day surveys (Roper Center 2008). (2) Most scholarly attention devoted to early voting has focused on the degree to which programs increase voter turnout. While many have argued that early voting fails to bring new voters to the polls (Burden et al. 2014; Fitzgerald 2005; Gronke, Galanes-Rosenbaum, and Miller 2007; Larocca and Klemanski 2011; Primo, Jacobsmeier, and Milyo 2007; Wolfinger, Highton, and Mullin 2005), others have reported that programs with abundant sites (Fullmer forthcoming; Losco, Scheele, and Hall 2010; Neeley and Richardson 1996) or sites in convenient areas (Stein and Garcia-Monet 1997) can improve turnout by several percentage points or more. Research has largely ignored the question of whether early voting alters the information environment in campaigns. Those who vote early may do so before important information becomes available in the final days and weeks of a campaign. Many have speculated that early voting may particularly affect presidential nomination contests, as support for candidates tends to be more unstable and the process often commences before candidates fully launch campaigns in respective states. I speculate that early voting should benefit early front-runners in these contests, as voters may cast early votes for these candidates before fully considering their less-known opponents. Examining exit-poll data from the 2008 Democratic primaries between Senators Hillary Clinton and Barack Obama, I find that Clinton indeed benefitted from early voting in several early primary states. Information Asymmetries When voters submit ballots early, they complete their civic duties ahead of schedule. With votes already cast, political campaigns essentially conclude weeks early for these citizens. There is no mechanism by which one can change a submitted vote; early voters can only wait and observe whether election outcomes (reported on Election Night or primary day) match their preferences. Of course, campaigns themselves do not end early. Candidates continue to fund television ads, participate in debates, and grant interviews and news conferences. The news media investigate voting records and past associations. Parties and outside groups remain active as well. Lacking any knowledge of late campaign developments, those who choose to vote early ultimately do so without the same information as Election Day voters. Late information comes in many forms during political campaigns. The term October Surprise has become synonymous with a news event holding the potential to influence an election's outcome. …