I can assume then, you want to see North America consumed by humanity and destroyed.

I think you mean America consumed by humanity and destroyed. Mexicans moving to the United States doesn't change the population density of North America at all. So changing US immigration laws to allow more Mexicans in, or changing --or not-- the 14th amendment's birth citizenship provision, will not further or retard the consumption and destruction of North America.

But we already know you are paranoid an irrational about population growth; that's a given. Will letting lots of people into the United States destroy it? In Wikipedia's list of 230 countries and dependencies ranked by population density, the United States clocks in at 178. More than half the countries in the world have a greater population density than we do. Countries like the Netherlands, Japan, the UK, Germany, Italy, Denmark, Poland, Portugal.... None of which as far as I know are being destroyed by humanity.

The US's population density (people per square km) is about 83. For comparison, Germany is about 230. Italy, 200. UK, 255. (Mexico, FWIW, is about 55.)

The sky is not falling, Chicken Little.