Presidential scholars argue that recent presidents are more contested than earlier presidents (Bose 2003; Lonnstrom and Kelly 2003; Murray and Blessing 1994). This is attributable to scholars' limited information--research in progress, data embargos, and classified documents--which prevents contemporary presidents' accomplishments from being revealed and settled. This position predicts that presidents since John E Kennedy are more contested than earlier presidents. By contrast, a more encompassing view on presidential contestedness identifies national historical eras in which a few presidents are considered great because they contributed successfully to solve dire national problems and secured the survival of the government (Milkis and Nelson 2003). But because contemporary reconfigurations of the executive office cannot anticipate, or be fully geared toward, subsequent problems, later White House occupants become identified as sources of growing governing problems following the solution to the crisis (Skowronek 2002). This position predicts the existence of eras other than the most recent one in which scholars increasingly disagree on presidents' accomplishments. The recency hypothesis can be true without the era hypothesis being true. But if the era hypothesis is true, it can subsume the recency hypothesis. The tests outlined here use data from presidential performance studies where measures of variance still have not been properly utilized.
Ever since ratings of presidential greatness began to be calculated in 1948 with the first study by Arthur M. Schlesinger, almost without exception scholarly raters--historians, legal scholars, and political scientists--have considered George Washington, Abraham Lincoln, and Franklin D. Roosevelt "great" presidents and James Buchanan, Andrew Johnson, Ulysses S. Grant, Warren G. Harding, Herbert Hoover, and, later, Richard Nixon "failures." Perhaps because of the repeatedly high correlations among more than a dozen expert studies rating presidential greatness (see Simonton 2006), no study has analyzed the disagreement over, or contestedness of, presidential greatness. Contestedness emerges when scholars rate presidents and disagree on an individual president's degree of greatness or failure. The concept of presidential contestedness therefore refers to the reputational variance or disagreement that occurs when presidential scholars assess the presidents. This variance is located among the presidents, and not among the raters, and must be addressed accordingly. (1) The absence of analysis of presidential contestedness is surprising, as so much of the debate in the presidential literature revolves around the achievements and debacles, triumphs and failures of the occupants of the White House.
As presidential scholars must consider a range of factors for each president, each scholar may assess some factors as more or less significant than other factors or even consider one factor to the exclusion of all others. The uneven performances of Harding, Lyndon B. Johnson, and Nixon, for example, are often addressed in the literature (e.g., Bose and Landis 2003; Greenstein 2004; Kessel 2001; Milkis and Nelson 2003; Schlesinger 1997). Whatever the choice of factors, the number of factors assessed, or the political bias of the scholars themselves, scholars are not likely to reach a complete consensus on any given president's degree of greatness or failure for two additional reasons. First, institutional factors, or "ambivalence" (Mansfield 1993), ensures that the president is, at the same time, both the head of state and the head of the government's executive branch. The duties of the head of state are expected to be far less partisan than the duties of the head of government. Second, the temporal factor ensures that through out his years in office, no president can be expected to perform equally well. Too many events and responses guarantee variation in accomplishments. …