[anigbrowl]

You still have a border, just like the 50 US states have internal borders with each other. Why haven't they ceased to exist as discrete entities?

Permeable borders abound in nature. Trying to obstruct the natural behavior of migration is as foolish as trying to halt the tides and arguably causes worse economic distortions than it solves.

[bluthru]

The Netherlands is better off for having dikes.

[s_y_n_t_a_x]

Because we're the United States. We're not the United Countries.

The "natural flow of migration"?