"Karen" is slang for a stereotypically rude, middle-aged white woman; the type who calls the cops on innocent black people.
Former assistant US attorney Lori Lightfoot not only is Chicago's first Black female mayor, but also the city's first to identify as lesbian.
So when White House Press Secretary Kayleigh McEnany called Lightfoot "the derelict mayor of Chicago" in a press briefing, the mayor hit back hard.
McEnany used the epithet following a question about President Trump's response to the death of black people from police brutality.
According to CNN, Lightfoot tweeted 'Hey, Karen.
Watch your mouth.'
