Jay, let me assure you and all our commentators that I would be similarly upset about a public school graduation in a mosque or in a predominantly GLBT Metropolitan Community Church. The doctrine of this particular church is, of course, relevant because it is recognized in the community as holding views that any reasonable person could predict would make some folks extremely uncomfortable. Secular venues are available and ought to be used.

Let’s turn to a few of your specific arguments and analogies.  Although
you may be right about “no preaching” occurring that day, we do know
from past events that church members (apparently not satisfied with
merely getting a rental fee from the government) sometimes  passed out
religious literature after graduation.  More significantly, this venue
is designed as a sacred space, a place created for worship.  How many
stained glass windows or giant crosses do you find in the average
grange hall or public swimming pool?  It doesn’t lose that character by
the nature of the event happening there.

I’m not troubled by a
mixed public school/private school basketball tournament that might
occasionally end up in the Catholic school gym.  However, as you know,
sometimes school districts do schedule events specifically to avoid
times, like Sunday mornings, where athletics might “compete” with
churchgoing, but then utterly reject accommodation claims of Seventh
Day Adventists whose worship is on Saturday.

And, please Jay, don’t go toward the darker side of your analogy with voting in churches. 
Americans United and other groups have been getting increasing numbers
of complaints in the past few election cycles about voters having to
confront even more than religious symbols on their way to the polling
stations located in religious institutions.  They may find
anti-abortion posters or even notices telling congregants how to vote
on ballot initiatives.