No trick. The US Constitution had a fugitive slave clause, allowed for the slave trade for 20 more years, and had the 3/5s compromise. The Northern dominated Congress passed and Lincoln offered a constitutional amendment which would have expressly protected slavery.
“Lincoln offered a constitutional amendment which would have expressly protected slavery.”
Wrong, Lincoln couldn’t offer up an amendment, he was not a member of the Congress of the United States.
How many times is the word “slave” or “slavery”ry mentioned in the confed constitution? How many times is it mentioned in the US Constitution? That’s why it isn’t enshrined - it’s barely even mentioned euphemistically. How can it be enshrined if they couldn’t even identify it by name?