Boycotts are bustin’ out all over. First, we had the police unions calling for a boycott of Quentin Tarantino’s December release of The Hateful Eight. Then, a little more than a week later, we had more than 30 football players from the University of Missouri boycott playing until the school’s president was fired or quit. Finally, the day after the success of the football boycott, presidential candidate Donald Trump, outraged because of the absence of Christmas symbols on Starbuck’s holiday cups, sorta called for a boycott of the coffee chain: “Maybe we should boycott Starbucks. I don’t know. Seriously. I don’t care.” But the tale of the two actual boycotts illustrates how a powerful political tool can be used effectively to bring about positive change in one case and be counter-productive and self-destructive in the other.

I believe in boycotts to fight social injustices because it’s an inexpensive grassroots way for average people to join together to affect change. When Indiana passed its Religious Freedom Restoration Act, a clear violation of the Constitution, boycotts against Indiana-based companies that took place in Oakland, Calif., San Francisco, Denver, Seattle, Washington, D.C., Portland, Ore., Connecticut and elsewhere, and by Disciples of Christ, Salesforce, Yelp, Angie’s List, Wilco and Charles Barkley, among others, forced the legislature to reconsider. The key to a righteous boycott is that the cause is about a greater social issue and not just an inconvenience, that it reflects the values in the Constitution and not just the private values of certain groups, and that the object of the boycott cannot be meaningfully persuaded in any other way. Usually, a boycott is a last resort.