Mexicans do not come here because Mexico sucks, they come here because living in Mexico on what they pay in Mexico sucks. They like to be Mexicans, but they dislike being poor Mexicans.
If Mexicans were to try to change their sucky economic system, then the US would be far more annoyed than it is by all the Mexicans coming here to find work. In Mexico, a very small number of people own everything, and they are closely allied with the US elites that own much of the US.
If one has American dollars, one can enjoy Mexico even more than the gringos do.
It is up to the US to make coming here without permission impossible, if Americans do not want all the Mexicans here.They come because they can.
If they couldn't, they wouldn't. Perhaps you will vote for someone who will make this happen. Or maybe they will lie to you about how they plan to enforce the law, as all the previous presidents and congresses have done.
The image you posted here is bogus, you know that.