The single biggest thing we can all do to fight injustice is to heal our hearts of the suspicion of the Other. To stop being scared of those who suffer from oppressions that we don't, or resentful of those who escape oppressions we suffer from.
Pitting us against each other is how the monsters stay on top. (They who have made monsters of themselves.) But walk around town and you will see that the basic human attitude we default to is "live and let live", despite all the poison our media and our politicians can muster. If the people chose overnight to follow that principle in their politics as well as their everyday actions, there would be a global bloodless revolution, and a better world.