As far as I know I have never visited a "crackpot site the Defenders of Slaverocracy", unless this is one.
It is EXTREMELY pretentious to assume you are capable of judging what someone else is capable of understanding based on a couple or even a few silly postings on a web-site.
Further, just because someone doesn't agree with YOU does not mean they do not understand the subject being discussed. There is always the possiblity, however remote, that YOU may be wrong, or that YOU have misinterpreted something.
Finally, it is NOT a pretense that the Constitution is simple and easy to understand. It is written in plain, simple language and only a lawyer, a politician or someone else who is trying to infringe on your (or someone else's) rights would endeavor to make it more complicated than it is.
Those sites are the sources of most of the canned quotes thrown up in lieu of argument here generally by those trying to defend the Insurrectionists of 1861.
My judgments are not limited to responses to small quotations. Nor do I consider myself that authoritative but when I see the same errors posted and reposted it gets tiresome in the extreme. One of the most egregious is the idea that since secession was not specifically forbidden it was allowed. This is like claiming that "divorce" should be mentioned in the marriage ceremony.
If the Constitution was so simple it would not have generated thousands of books trying to explain it. It is not and cannot be simple any more than the Bible could be.
As for the understanding of most people it is so limited as to be ludicrous. Even a site like this has people posting error after error which even non-experts can spot.
Oh, and perhaps you didn't know but the majority of the writers of the Constitution were lawyers. As were Jefferson, Hamilton, Adams, Madison, Monroe, Morris etc. etc.