There's a really simple and fair solution to this whole thing: when a person reaches the age where they can vote/sign contracts on their own/etc, they are asked if they agree to abide by the laws of the country, and to generally not try to destroy it. If they agree, they can stay. If they disagree, they get shipped out to whichever shithole country they prefer and they don't come back. If they renege on their agreement - say, after being brainwashed by a college professor who tells them the US is a fascist Nazi state that must be dismantled - both they and the professor (if they've signed such an agreement) are kicked the fuck out, preferably to China, Venezuela or another one of the socialist shitholes these people adore so much, and they aren't allowed back. Simple and fair. You don't get to enjoy the benefits of a civilisation while trying to destroy that civilisation.