Not having any idea what a Campus Card is, I thought I'd better find out. As with any piece of photo ID, it's always wise to discover in advance whether or not the fact I won't be carrying it with me at all times is in violation of some officious ordinance.
It actually took several minutes of hunting on the university's web site to discover what a Campus Card is. The information was hidden in an obscure MS Word document that the on-site search facility couldn't find but that Google could (and could display as HTML, too).
So, as a result of all this I now do know what a Campus Card is: it's an exercise in bureaucracy.