New York (CNN Business) Twitter last year proposed a policy that would have brought in tougher rules on dehumanizing language on the platform. Amid their deliberations, Twitter's top executives reportedly considered as an example Trump's comments — made during a meeting — about "shithole countries."

But Twitter decided not to adopt the sweeping proposal — and President Trump is still at it. On Saturday he attacked Democrat Elijah Cummings, whose congressional district includes Baltimore, and criticized the city. He said "no human being" would want to live there and said it was "disgusting, rat and rodent infested."

Indeed, Twitter confirmed on Sunday that Trump's tweets did not violate its rules at all.

Last September, Vijaya Gadde and Del Harvey, two senior Twitter employees, outlined a proposed "new policy to address dehumanizing language on Twitter."

The proposal defined dehumanizing language as "Language that treats others as less than human," adding, "Dehumanization can occur when others are denied of human qualities."