"No amendment shall be made to the Constitution which will authorize or give to Congress the power to abolish or interfere, within any State, with the domestic institutions thereof, including that of persons held to labor or service by the laws of said State."
All that says is that it's a matter for the states. Nothing in it says, "slavery shall be permanent forever and can never be outlawed anywhere." It says the federal government won't interfere with it.
My 546 ended, 'Abraham Lincoln was pro-slavery, as he supported a constitutional Amendment making slavery PERMANENT.'
The text of the Corwin Amendment did not indicate that it was permanent, Lincoln stated that in his inaugural speech:
understand a proposed amendment to the Constitution—which amendment, however, I have not seen—has passed Congress, to the effect that the Federal Government shall never interfere with the domestic institutions of the States, including that of persons held to service. To avoid misconstruction of what I have said, I depart from my purpose not to speak of particular amendments so far as to say that, holding such a provision to now be implied constitutional law, I have no objection to its being made express and irrevocable.