Simple solution.
Cut welfare, hospital treatment and school admission to illegals.
They will go home on their own.
Believe me when I tell you, if they think they can appease you they have utter contempt for you. If they think you are mad as a warm place and will never forgive them, then and only then will the cold fear running down their scarcely existent spines being to put a tiny smidgen of fear into them, and only then are they remotely tolerable as a class. Actually, come to think of it not they aren't, and should be tarred and feathered.