When whites get killed by non-whites, the Left invariable seeks to excuse it, or even (as in this case), justify it.
Add in some additional approved vs unapproved group membership, ie: Mexican (approved) vs Mormon (unapproved) and the murder-justification gets turned up to eleven.
Now while you make it clear that in Dagnabitt world Mormons are a nationality, in the real world Mormonism is just another religion some people subscribe to.
Some Mexicans killed other Mexicans.
Their problem.
But the Mexicans that were killed had anchor babies, even though they had lived in Mexico for over a hundred years.
Well, we do need to end that anchor baby problem, but other than that its a Mexico problem.
We need to seal our border and let Mexico's problems stay in Mexico.
The anchor babies or the religion of various groups of Mexicans don't make their problems when in their home country our problems.