The Guardian charted the reading levels of all State of The Union speeches and found that the “linguistic standard of the presidential address has declined.” Nathan Yau offers on explanation:
My guess is this has to do with changes in how we write and talk more than anything else. Lee Drutman and Dan Drinkard for the Sunlight Foundation ran a more rigorous analysis on Congressional records back in May, and the declining trend is similar.
The Dish 