“Structural racism” has become a buzzword in white progressive circles. But every time I push a white writer to break down the meaning behind the words without success, or I see a Black Lives Matter sign in an apartment window in a gentrified neighborhood where longtime residents of color are now priced out, I have to ask myself: How much we really know about the theoretically woke words we’re throwing around?

We’re finally starting to call out racial disparities, but do we understand the history that creates them? We pledge our allegiance to inclusiveness and shared power, but do we examine the roles our own lives play in maintaining policies, practices and cultures that continue to harm African-American friends and family, neighbors and co-workers?

It is for these reasons that I believe every white progressive (and, really, every white person) should see Bob Herbert’s new documentary, Against All Odds: The Fight for a Black Middle Class. Herbert presents an airtight case of structural racism in America — and it’s a case I’m laying out at length here in case you don’t see the film. If we are going to throw these words around, we better understand their meaning and use that understanding to inform the work that we — white people — must do.

When 6 million African-Americans fled the horrors of the South during the Great Migration, they discovered new forms of discrimination and exclusion in the North. Some found work in factories, but most worked menial jobs — as servants, janitors, drivers and cooks — while they were charged exorbitant rents for substandard housing in the worst neighborhoods.

One of the only pathways to the middle class that was available for black Americans was self-employment. But without access to capital, it’s hard to grow a business. Herbert’s grandfather managed to open an upholstery business that staved off the worst of the Great Depression for his family. His father, too, opened two stores in the 1960s and ’70s. But when his father was in a position to expand and compete with larger, white-owned businesses, he was locked out by the banks — and that was in New Jersey.

“They weren’t giving bank loans to guys who looked like my father,” Herbert says.

This lack of access to capital is a constant refrain throughout the black experience in America. When black families could finally afford to move out of ghettos, banks wouldn’t give them mortgages. Lenders took maps and drew red lines around neighborhoods where they wouldn’t loan to black families. (Hence the term “redlining.”) Moreover, the federal government wouldn’t insure home loans for black people — it was literally written into the Federal Housing Administration handbook, according to former housing organizer Jack Macnamara.

Read more: ‘Against All Odds’ Is Required Viewing for White Progressives