If I'm reading you correctly (I apologise in advance if I am not and please elaborate), you are inferring that admitting Mexicans will mean they will run the country into the ground. Most immigrants who came here since the country's founding came from dysfunctional places and/or situations when they left. Most people don't quit their homes and head far and away just for the excitement. Simple holidays take care of those interests. So far I've seen Mexicans work hard and contribute like any others who have come here. There will be some bad apples, but each group that has come here has had those too. They aren't the rule.