Over the last year, people across the country have taken to the streets in numbers unseen for decades to demand an end to police killings of unarmed people of color.

Meanwhile, the corporate media has forced the public to turn to the spectacle of presidential elections and all of its inanity. Inevitably, the movements seeking justice for those murdered by police and the media circus of presidential politics will meet in the streets of Philadelphia and Cleveland, the host cities of the 2016 Democratic and Republican National Conventions, making it a good time to reflect on the history and lessons learned from past political mobilizations.