The Right Can't Meme

To expand for a non-American who still may not understand the context:

The 13th amendment abolishes slavery in the US, where slavery at the time (prior to 1865) was based on the notion in the southern states that you could and should be owned as a slave if you were black. That included lifelong servitude of you and your children, any punishment deemed appropriate including severe physical punishments, and murder without consequence. Even if you were a free black man, and not shipped in from Africa like the majority of slaves, you could be captured by police and auctioned to someone to work on their plantation.

The 14th amendment establishes primarily that all persons in the US are equal regardless of the color of their skin. The bloodiest war in US history (Civil War, 1861-1865) was fought over the right for the southern states to declare it legal to own slaves, vs the northern states wanting slavery abolished federally. These amendments were ratified after the north won. Even after the war, it took another hundred years before Americans as a whole saw non-white people as equal. This and the next amendment were very much necessary to protect the newly found rights of former slaves.

The 15th, at least, is self explanatory.

The point of this meme is literally positing that it's ok to make black people slaves again if other parts of the constitution can change, because they're pretty boldly racist. There's not much else to it.