[eloff]

What's the alternative, give up on border control? How fair is it that people from India wait 20 years for a green card for following the rules while others just walk across illegally?

I don't understand the seeming position by some on the left that there's no need for border security.

[nradov]

I'm not opposed to border security. I just don't think that building a wall would be a cost effective means of achieving that goal. Plus there would be some negative environmental impacts.

[eloff]

It depends on the location and if it's combined with other things. An unmonitored wall would add little by itself.

In some places there already exist walls and they do help.