Is political rhetoric becoming less sophisticated over time? One interesting way to answer the question is to study the complexity of presidential speeches, from George Washington's first inaugural to the recent addresses of Barack Obama.
To do that, the site Vocativ used the Flesch-Kincaid readability test, which was developed by the U.S. Navy in the 1970s to ensure the simplicity of military instruction manuals. The Flesch reading formula is not a measure of vocabulary or the technical construction of sentences. Instead, it measures two variables—syllables per word and words per sentence. So a cryptic sentence like this:
As mist slunk in, the oiler on the rig slewed the boom of the crane.
actually has a lower (simpler) Flesch score than this sentence of equal words:
The cat was so happy after eating the goldfish that it made a big smile.
because happy, after, eating, and goldfish have two syllables, even though they're far more common than one-syllable words like slunk, rig, slew, or boom.
With that caveat out of the way, here is a look at presidential-speech complexity over time.

I was curious to see what the internet’s reaction would be to this piece. I think the dumbing down of speeches is fine—the cleaner the language, the more obvious the lie.

Joe Stracci