Public discussion of Arizona policy regarding non-native English-speaking teachers often presupposes that assessments of a teacher’s intelligibility are clear-cut and obvious. This paper discusses research indicating that such judgments are by no means straightforward; fair and accurate assessments also require consideration of the role of the listeners. For example, listeners’ attitudes toward non-native speakers may influence how they interact with non-native speakers, as well as the degree to which they acknowledge those speakers’ proficiency. Even without clearly negative attitudes toward the speaker, listeners’ perception may be biased by expectations so that the same pronunciations are heard as different depending on the listener’s beliefs about the speaker’s language background. In some cases, it is the perception of “standard” English that is inaccurate, effectively imposing a higher standard on non-native than on native speech. These findings suggest that impressionistic assessments of non-native English are very likely to result in discrimination.