HOUSTON — The devastation wrought by Hurricane Katrina became a rallying cry for African-American religious and political leaders here in President Bush's former hometown on Sunday, with pleas for charity mixed with a seething anger at the response to the crisis.

Many blacks voiced suspicions that thousands of people were left to suffer and die in the floodwaters because they were, for the most part, poor and black.

"'I'm not saying they didn't care. I'm saying they didn't care enough!" I.V. Hilliard, pastor of the New Light Christian Center Church in north Houston, thundered from the pulpit of his megachurch Sunday.

Interviews with African-American church leaders, local politicians and residents here made clear the damage that the faltering relief effort has had on their perceptions of the Bush administration. Bush and his chief political advisers have mounted an effort to try to woo more conservative black voters by encouraging black Republican candidacies and reaching out to black churches.

But their outreach efforts appear to have been significantly set back.