As Meteor Blades describes, for King, the fight for civil rights didn't end with black people being allowed to eat at lunch counters without being attacked. It didn't end with the right to vote (not that voting is by any means an uncontested right today). Time and time again, he made clear that civil rights and labor rights were tightly linked, saying, for instance, to strikers in Memphis, Tennessee, in March 1968:
Now our struggle is for genuine equality, which means economic equality. For we know now, that it isn't enough to integrate lunch counters. What does it profit a man to be able to eat at an integrated lunch counter if he doesn't have enough money to buy a hamburger? What does it profit a man to be able to eat at the swankest integrated restaurant when he doesn't even earn enough money to take his wife out to dine? What does it profit one to have access to the hotels of our cities, and the hotels of our highways, when we don't earn enough money to take our family on a vacation? What does it profit one to be able to attend an integrated school, when he doesn't earn enough money to buy his children school clothes?And the way to earning the money to buy a hamburger, go on a vacation, buy school clothes, would not, will not, be obtained without struggle. King saw that then in the lives of black people working hard and living in poverty, and we see it now in the fact that more than 10 percent of working families are poor—an injustice that once again falls heavily on people of color. No, Martin Luther King, Jr. did not use collective action to such great effect in the Civil Rights Movement and then forget about it or foresake it as an answer to economic injustice:
We can all get more together than we can apart. This is the way to gain power. Power is the ability to achieve purpose. Power is the ability to effect change. We need power…That struggle continues today, among the public sector workers, co-unionists with the striking Memphis garbage collectors, today under attack for having benefits and pensions; among fast food workers selling hamburgers and Walmart workers selling back-to-school clothes, themselves often short of money to feed and clothe their own families. Republicans and those bound to a vision of progress without struggle from below want us to forget that this was what Martin Luther King, Jr. stood for. It's our job to remember and honor that struggle.
Now the other thing is that nothing is gained without pressure. Don't let anybody tell you to go back on your job and paternalistically say, now, "You're my man, and I'm going to do the right thing for you if you'll just come back on the job." Don't go back on the job until the demands are met. Never forget that freedom is not something that must be demanded by the oppressor. It is something that must be demanded by the oppressed. Freedom is not some lavish dish that the power structure and the white forces imparted with making positions will voluntarily hand down on a silver platter while the Negro merely furnishes the appetite.
If we are going to get equality, if we are going to get adequate wages, we are going to have to struggle for it.