This is from Arthur Herman’s review of Schlesinger’s memoir, in 2000:
Thanks to Schlesinger, Roosevelt’s New Deal, which had begun to come under assault after the war, found a new historical warrant. Far from being an unprecedented growth of government, it was the culmination of American democracy, while its Republican opposition-”the Old Order,” as Schlesinger termed it-wound up on the rubbish heap of history. Schlesinger quickly expanded that warrant with three books on the coming of the New Deal published in the ’50s, while other liberal historians-including Harvard’s Frank Freidel, Columbia’s Richard Hofstadter and William Leuchtenberg-added their weight to the argument. Together these liberal historians consecrated the New Deal on the altar of American democracy and deeply marked the discipline of American history as a liberal preserve.
For my own part, I have a mixed view of Schlesinger. My first real exposure to him came from reading The Disuniting of America, a short book that said things that many conservatives had been saying for a long time when it was published, but which nevertheless represented an act of bravery to have a liberal say them. But I also read about Schlesinger and his methods in Coolidge and the Historians–in just a few pages, author Tom Silver showed how Schlesinger was brutally unfair to Calvin Coolidge and how this celebrated historian colored his writings in order to advance the interests of modern liberalism.