There are 11 million people in the US who "moved across borders when they needed to". Is there a country people want to migrate to that successfully keeps them out?
This is a fraction of the actual population which would happily move to the US but is kept away by immigration controls. 11 million on a population of 330 million is 3%.
Are you saying it's impossible to keep 3% of the people out?
It’s possible, just not worth the effort.
You think the whole population of Mex wants to "happily move" into gringolandia? Naive and arrogant at the same time.
I mean there are people from all around the world who would like to move to the U.S, I guess because their situations in their home countries suck enough to warrant it or some cases because they are personally ambitious and the U.S is seen as the place to realize that ambition. Many of them are not allowed to move though because of immigration controls.
Efforts to keep them out are constantly being sabotaged from within, it's not exactly proof we couldn't.