Donald Trump, the Republican presidential frontrunner, said on Saturday that undocumented immigrants were "poisoning the blood of our country," repeating language that has previously drawn criticism as xenophobic and echoing of Nazi rhetoric. Trump made the comments during a campaign event in New Hampshire where he railed against the record number of migrants attempting to cross the US border illegally. Trump has promised to crack down on illegal immigration and restrict legal immigration if elected to a second four-year term in office.