Despite separation of church & state, why fund-raising, campaigning, & endorsements in the Black church in USA?

For as long as I can remember, candidates for public office have commonly and casually visited African-American churches where there has been full liberty to campaign from the pulpit, get endorsements from pastors, and even "p the plate" for raising money for covering campaign expenses. Do Americans consider this some sort of "Affirmative Action exception" to the law? Or is it expressly permitted for all houses of worship? Or is this no longer allowed? (I KNOW it was common when I was in the States in the 70's in grad school and I visited an African-American church sometimes with my roommate because his uncle was the minister and he overtly told the people to vote for particular candidates and one time he did a "laying on of hands." He and the elders prayed over one of the men who was running for City Council and they "ordained" him for the "divinely appointed task". They prayed that God would give him energy and wisdom to persevere through the grueling campaign.)