I should clarify, since it's pointed out elsewhere that I did a bad job summarizing this: https://twitter.com/sandhawke/status/999301442165932032

Trump didn't say all immigrants were animals, but directly called MS-13 members "animals" and "vicious animals". This comment doesn't necessarily apply to all immigrants one could say, however it's been Trump's modus operandi to paint immigrants and entire ethnic groups under the guise of criminals, and I think there was a strong implication of this.