Objectives Building on work noting the difference between ambivalence and indifference, and long‐standing theories of partisanship, this article seeks to examine the extent to which ambivalence and indifference differ in their impact on the likelihood of individuals defecting from their party when voting. Methods Examining two national surveys, the voting behavior of ambivalent, indifferent, and one‐sided individuals are compared. Results It is shown that indifferent individuals are the most likely to defect from their partisanship and vote for the other major party or a third party and one‐sided the least. Conclusion Those who are indifferent toward the parties are distinct from those with one‐sided or ambivalent evaluations, and this difference leads to a greater likelihood of voting against one's party in presidential elections.