The Language of the State of the Union

The Language of the State of the Union - The Atlantic
FREEDOM: Perhaps the defining value of American society, the word is surprisingly rare in the nation's first century. 
It appears only once in the Constitution, and early presidents used it sparingly. 
Not until FDR placed the "Four Freedoms" at the heart of his 1941 State of the Union did the term become a staple of presidential rhetoric. 
Since then, it has flourished, but with a noticeably partisan tilt: the four presidents to use it the most are Eisenhower, Reagan, and the Bushes.
To date, Obama has used it less frequently than any president since Warren Harding. 
Benjamin Schmidt