The most decorated screen performance in the past year has been Philip Seymour Hoffman’s in Capote, the movie that tells the story of how the title character came to write In Cold Blood. Hoffman is a wonderful actor, and he is very good in the always intelligent and thoughtful Capote, which, truth to tell, is extremely boring. But here’s the thing. How hard could it have been for Hoffman to capture Truman Capote? He was one of the most easily imitated people of the 20th century — with such a singular voice and manner that he seemed like a cartoon come to life. A not-very-good Broadway overactor named Robert Morse won a Tony for playing Capote before Hoffman. Which suggests that for almost any performer, Truman Capote is the famous-writer version of Ethel Merman — the over-the-top musical-comedy star who could be imitated credibly by almost anybody on earth.