My grandparents on my mothers side came into this country almost 100 years ago legally. I agree people must enter legally, but if someone wants to get into this country bad enough all they have to do is come through any sea coast area or any area where there is not border patrol. Canada alone has thousands of miles where anyone could just walk across. We cannot man every mile of the border.
My mom's family moves back and forth from ND to Sask to MT to Alberta to WA to BC many, many times over the past hundred years and nobody says boo. No notice to any government agency, ever, except to pay taxes. It's treated by everyone as no different than moving from one US state to another US state. But let a Mexican do seasonal work here and cross back and forth each season and some see him as one of the four horsemen.
Get a grip. Immigration problems exist. But immigration is no where close to our biggest problem.