Research in the behavioral psychology of voting has found that voters tend to be poorly informed, highly responsive to candidate personality, and follow a "fast and frugal" heuristic. This paper analyzes optimal candidate strategies in a two-party election in which voters are assumed to behave according to these traits. Under this assumption, candidates face a trade-off between appealing to a broader base and being overly ambiguous in their policy stances. A decrease in the cost of ambiguity within this model offers a parsimonious justification for the increase in voter independence, candidate ambiguity, and party politics that empirical studies have revealed over the last five decades. I additionally argue a decrease in the cost of ambiguity is a natural result of the primary system, campaign finance reform, and changing media environment.