>What seems fair is to ban arbitrary "top-N" quotas. If you can get a job that pays you a living wage (such that you don't have to draw from subsidies), then you can stay without hassle.

Ok. I just know that this won't happen anytime soon. My top-N solution feels like something the current administration would not be too reluctant to implement. It also address the concern that foreign labor pressure downs salaries for US citizens.