allow a decision that may impact his employment and or company bottom line to be made by a democratic decision from a group of interns? Sorry - no way, no how do I put the fate of my employment at the end of the day in the hands of interns...

Now if this was minor playing with things that didn't matter (which is why they threw it to the group of interns in the first place) I'd let them brainstorm/group think, etc and guide them a bit and maybe let them go with something that I felt wouldn't work in the real world for their learning purposes - especially if they wanted to go completely against my guidance - in a learning environment (not real world business decisions) that failure on their part may teach them more than a manager telling them what to do for sure fire success. [of course I'm filling in some unstated details in my mind with these comments]