If illegal immigrants are really concerned about bring split up then they should have came here legally.
Like it or not, the American immigration system is not navigable for the majority of non-rich Mexicans. If the job market in your border town is so stuff that your only viable choice is to work up in the US, then you're going to choose to do it. If you were in the same situation that they were, you would agree that supporting your family and putting food on the table is far more important than respecting US immigration laws. We don't need to villainize them because they're just making the same rational choices that we would.
The only way to fix this problem is to accept more immigrants, and there's very little reason not to do so as long as we do it rationally. Increasing the amount of human capital in our economy is a good thing, which is why immigration waves historically lead to economic growth.
Unfortunately, if Annoying Orange actually keeps his immigration policy, our immigration reform is just going to become even more isolationist. If you want reform that works, you should probably vote for Bernie Sanders!