They know it's happening, that's why they're massively cutting back on their own immigration. They only want future immigrants like the Poles and Czechs because they supposedly assimilate better. You'll never hear weasels such as Tim Reid mentioning it though as they're too busy passing judgments on others.
The “Tea Party” isn’t “turn(ing) nasty”. People just want to win, rather than give their Country to loser marxist nobam-ites and their loser ilk.