No, that's not even it. They're not going to be convinced how stupid their bigotry is, not on a group level, and probably not even on a individual level except over time. I mean, that takes a change of heart; mere defeat won't do it.
Unfortunately, it has become a matter of civil liberties and the rights afforded to Americans under the Constitution. The point that must be made is not that bigotry is stupid, because all but the stupid people know that already. The point that must be made is that bigots, even if there are a lot of them, do not get to take away the religious freedom of a minority.
To be absolutely clear about it, it doesn't bother me if they want to put a mosque a couple blocks from Ground Zero; it bothers me that they want to put a mosque anywhere. The last thing we need is more damned mosques and churches. However, I recognize that the right to religious freedom trumps my concerns -- legitimate concerns, I think -- about how people use that freedom. I may hate your religion, but I'll defend your right to practice it.
And I say that knowing perfectly well that I'll never get the same respect in return from either the Muslims or the Christians.