imo., the language is still pretty close, more "turns of phrases" and such. Of course, original intent is by the intent of those at the time.
The Constitution was written in English that the average educated man of the day could understand. That said … the man that was considered educated in 1789 was far different than today. They had a firm base in classical philosophy, logic, history, etc. that is sorely lacking in the educational system today.
IMO, the best primer for someone to begin with …a "short-cut" of sorts ... and should be studied even before reading the Federalist Papers, Jefferson, and others is the philosophy of John Locke.
Locke heavily influenced not only the thinking of the founders, but the way in which they thought.
Keep smiling ... it'll just make 'em wonder what you're up to...