The problem is, Bush and his followers believe we should:
1. Let the market take care of it, or
2. Charity will take care of it, or
3. It's all the job of state and local govts. Don't blame FEMA (it shouldn't exist anyway).
It isn't that Bush is incompetent. Actually, his ideology says, what happened with Katrina is what should happen when there is a disaster. The idea is, all those people in New Orleans brought their own problems on themselves by being poor. The ideology says, poor people have problems because they "lack self reliance," drink, engage in sex or are otherwise morally inferior. And the ideology serves the purpose of protecting a constituency, the "haves and have-mores" from paying taxes. That's why they put a political hack in charge of FEMA. They don't think the government should help ordinary people when there is a national disaster.
Don't blame it on Bush's supposed incompetence. He isn't incompetent, and those who suppose he is will repeat their mistakes.