(CNN) Sen. Bernie Sanders said President Donald Trump's zero tolerance immigration policy shows Trump is thinking like an authoritarian who believes his anti-immigrant policies will help him win votes.

"He thinks as authoritarian types all over Europe believe, that if you foment anger against immigrants and show how strong and tough you are on those little children, that it will get you votes in elections," Sanders told CNN's Anderson Cooper on Wednesday on "AC360."

The Vermont independent has been a staunch critic of Trump's family separation policy, which led undocumented immigrant children to be separated from their parents at the US-Mexico border.

After mounting outrage from both Republicans and Democrats, Trump signed an executive order on Wednesday that is aimed to keep far more families together at the border.

Sanders noted the President's executive order does not address reunification for children already separated from their parents.

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