We are the wall.

I think that building the wall is stupidly expensive. A 3/4 mile long portion of the wall costs 11 million dollars.

It was an author of science fiction that had a solution. Orson Scott Card wrote the "Ender" series. In the book, China had invaded India. A movement was started by one of the characters: build a wall, mostly symbolic, one stone at a time. Citizens would carry a stone to pre-determined places...to disrupt the normal flow of operations of the Chinese military within the borders of India. They called it the "Wall of Freedom".

The Chinese first mocked the movement. Then, a directive was passed to military officials to arrest anyone carrying stones.

The reality: the cost of the wall could be absolutely nothing. Hell...we could paint rocks with the words "Free America" and make a line of them along the border. Enough people carrying and placing enough rocks?

We are the wall.