Found this interesting video following the USA / Mexico border - 2000 miles via helicopter.

It really opened my eyes on just how unprotected it actually is. It states of the 2000 miles, there is approximately 650 miles of fencing (or 32.5%). Of that 650 miles, only 350 miles (17.5%) is designed to stop human traffic (I.e proper wall) and 300 miles is simple vehicle barrier which humans can simply hop over.

That means 82.5% of the border between Mexico / USA is literally wide open for illegals to cross with ease.

https://youtu.be/RTQDwSVMdNg