Perhaps you'd best reread it all instead of cherry picking words from it, Dy. It doesn't institutionalize slavery. It prohibits the ability of the Confederate government from intervening directly beyond declaring any state seeking entry into the Confederacy possess a slave based economy. That isn't protection of the institution. That's protection of the Constitution which, conveniently enough, defines the national government. It was a caveat to prevent any future debates within the Confederacy at the national level about the character of the national economy. Which means that the economy would lie beyond intervention (to a greater or lesser extent via slavery and, later, via subsequent expansion of Confederate authority) by the Confederate government.
Note that I'm not defending the choice in words or intent. I'm merely stating that if we actually read the document as the attempt to create a government at the national level then we find quite a different message. What you're articulating here is exactly what the nutbag Protestants claim when they say that the Bible is anti-homosexuality. If one reads the whole Bible then we find a very different message (although not necessarily one of the endorsement of homosexuality).