How is Jake's closing argument indicative of it being his finest hour?

Jake's closing argument is his finest hour in several ways. Unlike the pompous approach of Buckley, Jake is sincere and humble. Yet at the same time, Jake is clever to introduce information that, while being objected to and having to withdraw, is planted in the jurors' minds. This includes Dr. Rodeheaver's bias against a plea of insanity. His closing is both brilliantly composed and executed without a flaw.