President Trump retweeted an attack on London's first Muslim mayor, Sadiq Khan, from Katie Hopkins, an English media personality known for making Islamophobic remarks.

Details: The president stepped up his Twitter attack on Khan later Saturday, calling him a "national disgrace who is destroying the City of London."

The big picture: Trump has a running feud with Khan, and he's attacked Khan on social media. But by retweeting somebody like Hopkins, he's amplifying her message of Islamophobia and giving it credibility.

Trump's previously tweeted in support of Hopkins as well - describing her writing about "U.K.'s Muslim problem" as "powerful."

The president has also tweeted: "The United Kingdom is trying hard to disguise their massive Muslim problem. Everybody is wise to what is happening, very sad! Be honest."

In 2017, Hopkins called for a "final solution" to Islamic terrorism. She was subsequently fired from her job at a radio station.

This article has been updated to include Trump's latest comments on Khan.

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