If it's evil, then the Union is evil in exactly the same way. It's constitution required perpetual enslavement of even more slaves than just the seceded states, and Lincoln was trying to amend it to make slavery even more secure constitutionally!
So claiming the Confederate constitution protected slavery more than the Union Constitution is just false. The CSA constitution was simply more explicit. Both constitutions protected slavery to the degree sufficient to keep it.
So claiming the Confederate constitution protected slavery more than the Union Constitution is just false/
Was a Confederate state able to outlaw slavery in that State?
They could do that in the Union. Many all but four of the States that remained loyal to the United States had outlawed slavery.