Political bias in the academy is a topic of great controversy. Many conservatives have argued that liberals dominate American campuses and use their classrooms to indoctrinate students or to discriminate against those with differing political beliefs. Liberals have responded by calling studies that purport to demonstrate these claims as flawed or as attacks on academic freedom. Regardless of the magnitude of campus political bias, it is ill-advised for the scholarly community to argue that it is immune from bias because scholars simply are fair. This article focuses on one element of political bias: partisan "outcome" bias in grading. We proceed in several steps. First, we provide an overview of the problem of grading bias and the concerns about political bias. Next, we consider the attributes of political grading bias and the forms that it can take. We present the analytics of partisan outcome bias and logic of using "paired" assignments to eliminate outcome bias. We provide data and analysis concerning outcome bias from a course Rom has taught. We conclude with a discussion of the ethics of grading.