efficacious - capable of having the desired result or effect; effective as a means, measure, remedy, etc
Malcolm X was efficacious for the civil rights movement. His ability to draw large crowds for his speeches, all over the country, was instrumental to the advocacy of African American rights.
Be peaceful, be courteous, obey the law, respect everyone; but if someone puts his hand on you, send him to the cemetery.
If you're not ready to die for it, put the word 'freedom' out of your vocabulary.
I don't even call it violence when it's in self defense; I call it intelligence.
A man who stands for nothing will fall for anything.