There's no better proof of the success of Trump's tactics than the imitation of his rivals. On Saturday night in South Carolina, with the notable exceptions of John Kasich (who tried with some success to play the adult in the room) and Ben Carson (who remains a strange wraith-like figure sleepily indifferent to everyone else on stage), the other candidates vied to outdo each other in insults.
I don't think there's ever been a presidential debate where so many of the candidates have called each other liars so many times. At some moments the trash talking and chest-puffing and general drama got so intense I thought this might be a fair approximation of West Side Story if you'd written it about two battling country clubs, the plutocrats versus the plutocrat flunkies. [...] [T]his was the debate where Donald Trump finally succeeded in bringing the whole party down to his level.