"His speeches left the impression of pompous phrases moving over the landscape in search of an idea. Sometimes these meandering words would actually capture a straggling thought and bear it triumphantly, a prisoner in their midst, until it died of servitude and overwork."
I believe (though I cannot find it) that another contemporary once described him as "a good, decent man who should be lieutenant governor of Rhode Island." That might have referred to someone else -- but sentiment seems accurate enough.
Harding's stated sins are generally that a) he was surrounded by utterly corrupt advisers (though nobody claimed Harding himself was), b) he was politically mediocre, and c) he was an intellectual lightweight. But, while not exactly calling him a world-beater, Ilya Somin makes the case that Harding might be one of our most under-rated Presidents.
Harding made a well-known speech advocating full legal equality for southern blacks in 1921, in Birmingham, Alabama. As W.E.B. DuBois pointed out at the time, Harding went farther in advocating equal rights for blacks than any other post-Reconstruction Republican president (the Democrats, at that time the party of southern whites, were even worse). Indeed, no president went as far as Harding in advocating equal rights for southern blacks for several decades thereafter. Harding also lobbied hard for a federal anti-lynching bill to curb the rampant lynching of blacks by whites in the South - again, the first post-Reconstruction president to do so (the bill passed the House, but died in the Senate due to the threat of Democratic filibusters). As DuBois pointed out in the linked article, Harding was not wholly free of the racism common among whites at the time. But he was a lot better than the vast majority of his contemporaries.
Nor were these Harding's only positive aspects. As Gene Healy discusses in his interesting recent book, The Cult of the Presidency, Harding is also notable for reversing the severe violations of civil and economic liberties that had proliferated under his predecessor Woodrow Wilson. It's easy to belittle Harding's campaign slogan - "Return to Normalcy." But Harding's notion of "normalcy" included an end to the imprisonment of political dissenters (such as Wilson's notorious "Palmer Raids"), abolition of wage and price controls, and the reversal of Wilson's numerous illegal seizures of private property. As David Bernstein and I briefly discuss in this article, Wilson's administration was also highly racist and segregationist even by the standards of the day; here too, Harding was a sharp contrast.
All fair points, and worth considering. I particularly was unaware about his efforts on behalf of racial equality.
So let's have a cheer for President Harding: he really wasn't as awful as everyone makes him out to be!