Willmoore Kendall said that if Brent Bozell had stayed clear of the Buckley circle he might have become a fine senator from his native Nebraska. Kendall was wrong. I can’t imagine Nebraskans electing a theocrat—and a Roman Catholic one at that. But Buckley was responsible neither for Bozell’s theocratic views nor his conversion to Catholicism. Indeed, Bill Buckley was the best thing that ever happened to him. Their relationship was perhaps the single constant in Bozell’s tumultuous life that included conservative stardom, mental illness, and religious repentance, and is constantly in the background of Daniel Kelly’s impressive new biography, Living on Fire: The Life of L. Brent Bozell Jr.

Bozell arrived at Yale in 1946 after naval service in the Pacific. His friendship with Buckley was inevitable: both veterans, both favorite students of Kendall, both pronouncedly...