Walls and fences work everyplace they've been tried including here in the US. The reason Democrats are scared like hell of them is because they do work. Democrats don't mind policies against their desire to flood our country with foreigners because they can change them once in power, but a wall would be much more difficult to remove.
But of course, you believe anything a Democrat tells you, so keep parroting that walls don't work. Statistics say otherwise.
An unmanned wall can be defeated with a ladder! A LADDER. You still have to man the wall with enough men, at all times, to stop people. I don't need a Democrat to tell me that. I can go to the border and film it for you, lol. Walls don't work.
For a taller wall, they drive a big box truck up to the wall and haul the ladder on top of the truck. Then they use ropes to lower themselves down to the other side.
For the lower walls they just use two ladders. Once they get up the first ladder, they throw the other ladder over the wall and crawl down. Or they use blow torches to cut through the wall. Or they tunnel under. But mostly they go over.
You need something better than an unmanned wall. You know, something that hasn't already failed.