Two observations come to mind. First, it's remarkable how often those who are more conservative are asked to view the speech of those more to the left as nothing more than part of a "conversation" -- and how the episode is posed as a test of open-mindedness. It's hard to imagine it working the other way, however -- students (or alums) of U Cal-Berkeley being asked to tolerate, say, a speech from Sarah Palin on the grounds that it's nothing more than part of a big "conversation." And make no mistake -- they wouldn't tolerate it.
The second, larger issue raised by the Notre Dame debacle is just how much the Church or its institutions can countenance (or even celebrate) views that are antithetical to Church teachings without losing its identity. It's the religious equivalent of wondering just how big a "tent" the GOP can have and still remain the GOP.
Certainly, any group based on ideas or beliefs -- religious or political -- generally wants to grow its membership, because a larger membership means enhanced influence. But where is the tipping point, where expansion means changing the core nature of the group to the extent that it no longer stands for what it used to?