Americans perceive political incivility as a major problem in US politics. Research shows that incivility has consequences, many of which, though not all, detract from well-functioning electoral politics and democratic governance. Prior research demonstrates that both Democrats and Republicans evaluate the same uncivil speech as more uncivil when perpetrated by a political opponent rather than a fellow partisan. Building on research in identity theory (IT) examining how the prominence and salience of diverse role identities moderate individuals’ responses to non-verification of those identities, we investigate whether the tendency to attribute lesser incivility to the same uncivil speech when perpetrated by a fellow partisan (vs. opponent) is itself shaped by the prominence and salience of Americans’ political identities and by the degree to which they perceive these identities as moral identities. Finding strong support for some of our moderation hypotheses, but mixed support for others, this work contributes further to understanding the meanings Americans attribute to their political identities by offering possible explanations. It also suggests optimal measures and designs for future research testing these explanations.