SACRAMENTO  Ron Allen says he knows all too well the ravages of drug addiction.

“I was a pastor on crack cocaine, sir,” said Mr. Allen, who says he has been sober for 11 years and now identifies himself as the bishop of the International Faith Based Coalition here. “Drugs have no religious preference.”

And while crack cocaine laid him low, Mr. Allen says his first drug of choice was marijuana. So it is that Mr. Allen and a cadre of other black pastors, priests and other religious leaders have bonded together in recent weeks to fight what they see as a potentially devastating blow to their communities: Proposition 19, the California ballot measure that would tax and regulate marijuana.

In doing so, Mr. Allen and his followers have opened a new, potentially crucial front in the battle over Proposition 19, pitting those afraid of more widespread use of the drug versus those who see legalization as “an exit strategy in the war on marijuana.”

Mr. Allen has been particularly critical of Alice A. Huffman, the president of the California branch of the N.A.A.C.P., who has been vocal in her support for the measure, casting it as a potential victory for civil rights that could help reduce the number of young black men jailed on marijuana-related offenses.