Robert Shogan is correct that President Harry S. Truman did more for the cause of African American rights than his predecessor Franklin D. Roosevelt or his successor Dwight D. Eisenhower.
Yet Shogan is unfair to Lincoln's Republican successors, who had better records than Democratic presidents before Roosevelt. He quotes W.E.B. DuBois in 1922 as commenting that neither Republican nor Democratic presidential candidates were to be trusted, without noting that DuBois in 1912 made the mistake of supporting Democrat Woodrow Wilson, who segregated the federal civil service — the worst act of any post-Civil War president.
Shogan also fails to points out that Truman, as late as the 1950s, called Rep. Adam Clayton Powell Jr. the "N-word." Like Abraham Lincoln, Truman's support for civil rights was a triumph of principle (plus a measure of political calculation) over personal prejudice.