Four protests that triggered change - and one that didn't

From Black Lives Matter to Belarus and Hong Kong, protests have barely been out of the news in 2020.

But how often do protesters achieve the change they demand? How does people power transform history?

A political historian and an expert on race and media look back on previous protests that did - and didn't - achieve their goals.

Video by Susie Smith

Produced by Tiffany Wertheimer