Guns on campus: both a protected and a repugnant transaction?

On July 1 the new Idaho law explicitly allowing guns on college campuses went into effect.  Weapons on campus are now allowed in several states, and explicitly prohibited in others, so it is both a protected transaction and a repugnant one. Below is a sampling of stories.

Gov. Butch Otter signed a law making Idaho the seventh state to allow concealed weapons on college campuses.
"Idaho now joins six other U.S. states that allow the “concealed carry” of weapons on public college and university campuses. All 50 states have laws permitting the carrying of concealed guns in public, but the restrictions differ significantly from state to state. In 21 states carrying a concealed weapon on campus is affirmatively banned."

Here's an (outdated) map showing which states are which as of 2013.

Outgunned, for Now

When May I Shoot a Student?

Here's the concealed weapons FAQ from the Idaho attorney general.

And here's the relevant section of the law:

18-3309. Authority of Governing Boards of Public Colleges and Universities Regarding Firearms 
(This Law Becomes Effective July 1, 2014)

(1) The board of regents of the university of Idaho, the boards of trustees of the state colleges and universities, the board of professional-technical education and the boards of trustees of each of the community colleges established under chapter 21, title 33, Idaho Code, hereby have the authority to prescribe rules and regulations relating to firearms.

(2) Notwithstanding any other provision of state law, this authority shall not extend to regulating or prohibiting the otherwise lawful possession, carrying or transporting of firearms or ammunition by persons
licensed under section 18-3302H or 18-3302K, Idaho Code.

 (a) However, a person issued a license under the provisions of section 18-3302H or 18-  3302K, Idaho Code, shall not carry a concealed weapon:

 (i) Within a student dormitory or residence hall; or

 (ii) Within any building of a public entertainment facility, provided that proper signage is  conspicuously posted at each point of public ingress to the facility notifying attendees of  any restriction on the possession of firearms in the facility during the game or ev