Your comment makes me think in a way I had not considered seriously...thanks.
The same method of invasion and takeover is being perpetrated by Islam, in all current cases with the encouragement of the host nations. Liberalism in action (and liberalism is practiced by the GOPe too, see open borders and "religion of peace") is suicide of Western Civilization.
Suicide of the West: An Essay on the Meaning and Destiny of Liberalism: James Burnham