Although it seems backwards, building a border wall on the southern border between the United States and Mexico would deter illegal immigrants from the south from returning home. The statistics I posted on my earlier argument highlighted the fact that more Mexican immigrants were leaving from the US to Mexico than the other way around in the year 2017. A border wall would stop the majority of illegal immigrants from leaving back across the border.

You brought up Visa overstays in your last sentence and I would like to clarify something. A wall will not affect any of the illegal immigrants who overstay Visas. They come to the country legally and always have (those who get Visas and overstay them). In the article that I linked to my argument (which went more into depth about Visa overstays) it says that roughly 600,000 immigrants overstayed their Visas to the United States in 2017.

A little under half of all illegal immigrants travel to the United States in 2017, traveled here legally by legal means and overstayed their visits in the United States. They overstay their Visas and purposefully stay here illegally, knowing that there isn’t much to be done to stop them. An article will be linked below showcasing Visa overstay statistics among other things, from 2017.