How is this any different with slave states wanting to enforce their slave laws on non-slave states by requiring them to turn over run away slaves? Since non-sl

How is this any different with slave states wanting to enforce their slave laws on non-slave states by requiring them to turn over run away slaves? Since non-slave states no longer had slavery, there was no crime committed when slaves ran away and traveled to the free states. Slave states where trying to push their state laws as federal laws and circumventing non-slave state sovereignty and federal laws.