The problem is not my comprehension. The problem is you thinking you can pretty up what I summarized and pretend it means something completely different.
Nope, it's your reading comprehension. What I said was that ideology is not party, and that Republicans have in the past sometimes been liberal while Democrats have sometimes been conservative, depending on the times, the individuals, and the issues. Specifically, on the issue of slavery, I noted that all of the Republicans were liberals, and many of the Democrats (though not all of them) were conservative.
Equating liberal with good and conservative with bad is NOT what that means or implies. You just read it into it for no better reason than that you, personally, don't like slavery, and so you find it hard to accept that supporting slavery was, at that time, a conservative position. (Now it's not. Now it would be a radical right-wing position. But when slavery was still a living issue, it was.)
If I were equating conservative with "bad," I would also say that conservatives practice every evil from rape to bank robbery to spitting on little old ladies to cannibalism. Obviously, that's not what I'm saying.
Obvious, that is, to everyone but you.