For example, Morris gives you no sense of what America was like in 1980 when Reagan was elected. Nowhere does he paint this picture. Lots of presidents are re-evaluated by history. Recently Eisenhower's and Truman's reputations have soared. Kennedy will be seen, in retrospect, to be a mediocre president, elevated solely by martyrdom.
Younger historians love to overturn the existing intellectual consensus.
And in this case, the historical consensus is so out of line with the facts. So Morris's book is a failed attempt to explain how a dummy could be so successful. He attributes it to Reagan's good looks, acting skills and tenacious will. Morris can't account for this. That's why he got writer's block for years.