Heresy?

Here's Tony Campolo commenting on the meaning of Katrina and the role of God:

Perhaps we would do well to listen to the likes of Rabbi Harold Kushner, who contends that God is not really as powerful as we have claimed. Nowhere in the Hebrew Scriptures does it say that God is omnipotent. Kushner points out that omnipotence is a Greek philosophical concept, but it is not in his Bible. Instead, the Hebrew Bible contends that God is mighty. That means that God is a greater force in the universe than all the other forces combined.

In scripture we get the picture of a cosmic struggle going on between the forces of darkness and the forces of light. The good news is that, in the end, God will be victorious. That is why we can sing in the Hallelujah Chorus, "the kingdoms of this world [will] become the Kingdom of our Lord."

Now, I'm no theologian (Campolo, I believe, is), but this strikes me as heresy. God is omnipotent. If not, he's not God. The cosmic struggle in the world is not between God and Satan, it's between God's representatives (redeemed man and the heavenly hosts) and Satan. God, by definition, struggles not.

Discuss among yourselves.