I think President Bush is simply being "politically correct". Frankly, I see no real value in a Christian wanting to become president. Unless your'e the D. James Kennedy type who wants to "win back America for Christ",I don't think Jesus would be impressed with such ambition nor calls us to a political agena. To many areas for corruption and comprimise, IMO.
How quickly some forget what Jesus said, "My Kingdom is not of this World". Yes, you could argue we are 'salt and light' in the world and should bring our message into the 'political world view'. I have no problem with that. Billy Graham is a fine example. He didn't have to 'please anyone' other than God. Elections to office happen because of three things; money, power and political salesmanship. I highly doubt that anyone running on a Gospel Ticket will ever be elected to the Presidency.
They have too many other people they have to please that could care less about Jesus Christ. American politics follows the art of comprimise.
Jesus isn't into comprimise, but is into righteousness.
My 2 cents. (Don't spend it all in one place)

In Jesus,
Bob