It also ran on TV right around 1969 or '70 and I taped it (audio only). In one act of the monologue, Holbrook drew on Twain to comment on the Vietnam War, still slogging onward at the time.
His comment via Mr. Twain was (after a suitable prelude),
"Even though the war be wrong, we are in it! We must fight it out. We cannot retire without dishonor!" Twain then comments on his own quote, "Why, not even a burglar could have said that better."
Let us not forget who the burglars are this time. Never, ever forget who and what mass-murdered so many people on September 11, 2001.