Frankly, anyone who would stop donating to UR because the president held a rally on campus is an idiot. The school had nothing to do with it either way ? the president's people selected the site and that was that. It's like when the federal government decides it wants to build a facility on your property. Guess what? You're moving.
In a similar vein, I am willing to wager that UR officials were not out there urging Mitt Romney to come to campus either. Perhaps they would have had more leeway to reject him if they wanted to, but that also would have been stupid. Take the exposure regardless of which candidate or party it is. And if you get them both, even better!