At a campaign rally in New Hampshire last Saturday, the former president Donald Trump repeated a claim he made back in September: immigrants coming to the United States, he said, are “poisoning the blood of our country”. The phrase is particularly disturbing as it evokes Nazi language about blood and nation. The last time Trump uttered this “poisoning the blood of our country” phrase, criticism from historians and civil libertarians was swift. This time, Joe Biden’s re-election campaign saw an opportunity and pounced. “Donald Trump channeled his role models as he parroted Adolf Hitler,” a Biden-Harris 2024 spokesperson wrote on...