Validity and Reliability of Identifying Presidential Positions on Roll‐Call Votes in the Age of Trump

Presidency scholars have interpreted Congressional Quarterly’s (CQ) studies of how often members of Congress support the president’s position on roll‐call votes and how often he prevails as valid and reliable measures of presidential support and success. This interpretation assumes that the president’s position‐taking behavior is honest and consistent and that he contributed to and understands the policies he purports to support. Trump’s behavior belies these assumptions. His erratic behavior highlights the fundamental importance of reliably observing this aspect of presidential behavior. This article assesses the validity and reliability of CQ’s Presidential Support studies and compares CQ’s list of presidential position votes in 2017 to the list identified by FiveThirtyEight. The analysis finds a number of inconsistencies in how CQ identified presidential positions over time and that only about 50 percent of votes identified in the two studies are on both lists. These results raise questions about whether presidential support scores and success rates in recent years are comparable to those in previous decades.