Mayer notes that his "rating system differs from others in deemphasizing “leadership” per se and instead emphasizing fidelity to the Constitution." By that standard his "Great" presidents are Washington, Jefferson and Lincoln. His "Failures" comprise, in descending order, Theodore Roosevelt and Woodrow Wilson (tie), Franklin Roosevelt, Lyndon Johnson, Richard Nixon, and (last and least) Bill Clinton. I find no fault with Mayer's rating scheme or his results.
Mayer's designation of Lincoln as a "Great" will rankle many libertarians, especially the anarcho-capitalists who hang around the Ludwig von Mises Institute and LewRockwell.com. (My latest disparagement of their anarcho-romanticism is here. See also this piece about slavery.) Mayer says of Lincoln:
[H]e does not warrant the severe criticism that certain libertarian scholars have given him, calling him “tyrant” or “dictator” and erroneously claiming that the modern regulatory/welfare state began with the Civil War. Rather, I maintain, Lincoln did indeed save not only the Union but also the Constitution itself, from the most formidable internal threat it has ever (yet) faced.In the end, what matters most is whether a president preserves liberty, and even advances it. How he does it is less important than whether or not he does it.
Finally, happy 274th birthday to George Washington.