Nice attempt at a straw-man there, you are better than that.
It is not like the Discovery Institute and The Freedom Alliance were not working in conjunction to host this event.
Per the contract it is the promoter’s responsibility to see that all the provisions of the rental contract are met. They did not do that and the event was cancelled.
And this is forbidden in the contract, if indeed it is so?
You've read their contract, have you?
Not a strawman at all, as though such an accusation is going to make my example invalid, but tossing that in is fun and meaningful, I suppose.
You're arguing an illogical position, that a non-signatory to a contract can be bound by that contract or that a person signing a contract has to control or is responsible for third party actions.
Maybe you could could explain how that logic works before I'm the reason for an upcoming event at the Center gets canceled because of my unapproved announcement.