This is The New Yorker Radio Hour, a co-production of WNYC Studios and The New Yorker.

Welcome to The New Yorker Radio Hour. I'm David Remnick.

It's been a decade since a slogan, a hashtag, made its way around the world.

And unlike most hashtags, this one stuck.

Three words, Black Lives Matter.

Black Lives Matter doesn't sound like a radical proposition.

In fact, it should be self-evident.

But those words became a rallying cry.

Black Lives Matter.

Black Lives Matter. Black Lives Matter! Black Lives Matter!

Then an organization, and then a movement that rivaled the civil rights era of 50 years earlier.

The phrase Black Lives Matter first appeared in a Facebook post after an unarmed teenager, Trayvon Martin, was shot and his killer walked free.

After George Zimmerman was acquitted, I think there was a real sense, I mean, I can speak for

myself and other black folks that I know, not just that justice had not been served, but that that verdict essentially said to

black people across this country that our lives don't matter, that we can be holding a skittles

and an iced tea and still be killed, that we can be sitting in our cars and gas stations listening

to loud music and be killed, that we can be knocking on

someone's door and asking for help and be shot.

Alicia Garza was one of the co-founders of Black Lives Matter, and we spoke in 2016.

And at its height, in the worldwide protests that followed George Floyd's murder, Black Lives

Matter also became a lightning rod

for all kinds of backlash, including a newly energized white supremacy movement. And this week,

...