Vase.

Rhymes with face.

Not only does it explicitly require non-slaveholding states to return fugitive slaves to their oppressors

The Fugitive Slave Law wasn’t part of the Constitution.

but it has multiple mechanisms intended to ensure the dominance of slave states in the federal government.

Again, not part of the Constitution. Those were the various compromises that the South kept getting pissy about foreseeing the end of Slavery, so they kept threatening rebellion.

If anyone tries to tell you the civil war was about states rights, not slavery… These are pretty obviously about slavery. But if they don’t believe that, just let them read the Southern States Declarations of Secession. They say what the civil war’s about in their own words.