I don't think you know what you are talking about. 

Unrestricted illegal immigration into the southern states has destroyed the careers of 100's of thousands of skilled tradesmen in the construction industries., among others.

It has fostered a cynical view of the law of the land, with elected officials and bureaucrats openly choosing which laws they choose to adhere to. 

It has drained Mexico and other Central American countries of millions of hard working people looking to improve their lives, when those countries would arguably be better today had those people stayed home and fought to improved life there. 

It has shown the millions who made the effort to immigrate legally that they were fools to do so....that their adopted country can't be trusted to treat all equally. 

Whether you agree with his efforts to date, Trump is simply trying to return to the rule of law. Trump may not be the solution you'd choose but he certainly is not the cause of America's immigration problem.