His reputation as a realist?

Hunh?

The book does not demonstrate that the president is in a state of denial. His almost exclusive and increasingly grating reliance on the rhetoric of unwavering resolve may be mistaken. It certainly has undermined his reputation as a realist. But he believes a president must be "the calcium in the backbone" of the nation, so the resolute face that he thinks he must show the nation does not preclude private anguish.

And that paragraph undermines George Will's reputation as a sentient human being.