Outrage over George Floyd's killing by police catapulted Black Lives Matter (BLM) into one of the largest protest movements in U.S. history, with angry crowds chanting the slogan at rallies from Los Angeles to Washington.

But five years on, the protesters are gone and an iconic monument outside the White House has been erased, leaving many to wonder if the movement blew its chance for historic change by failing to win over the American public.

"It's very easy to wear the T-shirt, utter the slogan, but then you looked at what they were asking for," Yohuru Williams, who runs the Racial Justice Initiative at the University of St Thomas, said.