What is the problem with current Mexican immigration?

there are to many of them Interesting question, I hope you know this usually involves some politics and there is no one right answer, no matter what, it is every ones personal opinion. I am somewhat of a liberal and do not believe we should block borders. Yet I believe we need to have some strict conditions on who is allowed to enter our country. Elaboration: no criminals(I know this is broad trying to keep it simple.)