The problem is we should have no illegal problem with a naturalization clause; and, we don't have a common defense issue on our border it is a refugee issue.
It's not just an issue about people of Mexican origin. You have drugs, you have human trafficking, there are people coming across the border from multiple countries and regions like Central America, South America , ME, Europe, etc. Just on the other side of the border towns are run by drug cartels as much as they are by the Mexican government. Then you have M.E. terrorist groups like Hezbolla ,which have set camp In parts of Mexico who can make deals with Cartels.
The Mexican Government itself cannot control what is going on inside it's own borders, and they have no idea who is going across their northern border into the U.S., nor do they really care. So maybe when they can correct all of that, we could begin to talk about not needing a secure border.
To say its just an issue with a naturalization clause and refugees is simply choosing to look at the tiny piece of the picture you want to look at.
So really? we should naturalize everyone who comes across our border? and what if they happen to not be Mexican? who gets to decide which ones to naturalize? See, this is why we have an immigration policy where we allow a million immigrants into the US a year. By the same token, we also have the right to deny people entry, much as every other country in the world does.