I agree in general, change.org and sites like it should not be blocked for their content. If the site was being used maliciously, perhaps the block was appropriate. I don't know. If access is a privilege, perhaps the privilege was lost through bad behavior.
I'm more concerned (as I'm a college IT administrator myself) on the question of censorship. From what I understand censorship is only a First Amendment issue when the government is doing the censorship. Is this an appropriate viewpoint? At what point am I as an IT administrator, or the system I manage, infringing on the first amendment rights of a member of the college community? Does it only apply to state schools, or to any school which accepts government funding? Some college administrators are state employees. Does it only count as government censorship if a state employee (or a system managed by said employee) blocks a specific web site?
From a technical viewpoint, IT Administrators have an obligation to protect their infrastructure and their community members from threats, both perceived and actual. Consider for a moment the viewpoint that the messages from change.org were deceptive, harrassing, or threatening in some way, either politcally or technically. If so, was it correct to block change.org?