Which president is the author of this speech?

Here, I am predicting the authorship of a given presidential speech using previously known speeches of each president from 44 of the US presidents, using TDM and using the simple Naive Bayes classifier The methodology only depends on the frequency of the usage of specific vocabulary of each president, this technique assumes that each president have some distinct words that being used by him systematically throughout his speeches... Let's see how well this technique preforms...