Key word "tried" and failed. A single line defense is fucking stupid both because it wastes taxpayer money, at least outside cities, and because it does nothing to stop those overstaying visas or those smuggled in on boats, planes or from Canada. If they really wanted to fix the problem they'd start arresting every business owner who hires, harbors or otherwise makes money from illegal immigration.
Unsurprising that you couldn't come up with a single thing they've fixed. Also unsurprising that you label me an "Insane Leftist". It means you're just another angry, lying scumbag liar whose own family won't talk to you. I'm guessing you are a Euro-American male, over 65, mediocre career, bitter and angry at your life's failures yet too fucking cowardly and stupid to accept responsibility for your own actions. You'll be better off dead as will everyone who ever knew you. People will clap upon hearing your passing. Sad.