ALL nations enforce their borders but the reason why liberalfilth freak out when America does it is quite obvious: they have proven to be such violently self-loathing traitors to this country (who need "safe spaces" whenever they see the WAAAAYYYCIST American flag), they HATE the idea of America exercising any sovereignty at all. They want this country to be handed over to the American-hating dregs of the third world they venerate. That's why, if you are a liberal reading this post, you are dripping with so much hatred and treason to your own country (like Obamaggot), I wish you dead of the terminal illness of your choice.