Prophetic speech is political speech, just not in the way we think.

The same Dr. King that said:

“Ultimately a genuine leader is not a searcher for consensus, but a moulder of consensus.”

Where Do We Go From Here? (1968)

said this:

“Nowhere is the tragic tendency to conform more evident than in the church, an institution that has often served to crystallize, conserve, and even bless the patterns of majority opinion. The erstwhile sanction by the church of slavery, racial segregation, war, and economic exploitation is testimonial to the fact that the church has hearkened more to the authority of kthe world than to the authority of God. Called to be the moral guardian of the community, the church at times has preserved that which is immoral and unethical. Called to combat social evils, it has remained silent behind stained-glass windows. Called to lead men on the highway of brotherhood and to summon them to rise above the narrow confines of race and class, it has enunciated and practiced racial exclusiveness.
We preachers have also been tempted by the enticing cult of conformity. Seduced by the success symbols of the world, we have measured our achievements by the size of our parsonage. We have become showmen to please the whims and caprices of the people. We preach comforting sermons and avoid saying anything from our pulpit that might disturb the respectable views of the comfortable members of our congregations. Have we ministers of Jesus Christ sacrificed truth on the altar of self-interest and, like Pilate, yielded our convictions to the demands of the crowd?”

“Transformed Nonconformist,” in Strength to Love (pp. 16-17)

We need Dr. King in context.