Barack Obama’s campaign catchphrase “Yes, we can” is an English translation of the Spanish “Si, se puede”, a phrase attributed to American labour and civil rights activist César Chávez. In fact, it was coined by Dolores Huerta, the subject of Peter Bratt’s essential documentary. A luminous, charismatic and principled mother of 11, she embedded herself in farming communities, advocating and fighting for worker’s rights and insisting that “labour movements are social movements”. The film doesn’t exactly reinvent the form, though it does attempt to reconfigure history by writing Huerta back into it, acknowledging that women are often written out.