How is wetback as a slur even remotely comparable to the N-word.
Are you serious or just trolling? Both are used by white supremacists to describe the respective ethnic minorities as a dehumanizing put-down.
"Both are used by white supremacists", except in this instance it's Blacks and Hispanics using it against each other, so I'm not sure why you brought whites into it.
A point of history, per se: in this case, the terms were originated on the white side as slurs, and later they are used by each group to offend the other.