It has long been argued that U.S. states' differential performance on nationwide assessments may reflect differences in students' opportunity to learn the tested content that is primarily due to variation in curricular content standards, rather than in instructional quality or educational investment. To quantify the effect of differences in states' intended curricular goals on test item performance in the mid-to-late 2000s, we use fractional logit regression of state-specific mathematics item difficulty values on a measure of content emphasis in state elementary school mathematics curricular standards documents. Finding weak but positive associations between content emphasis in state standards and proportion-correct item difficulty, we conclude that variations in states' intended curriculum content, alone, appear to have had limited influence on cross-state mathematics test item performance during the time frame examined. Implications for cross-state assessment are discussed.