John Bolton flirted with running in 2012 if no one was sufficiently hawkish for him, but he relented and eventually endorsed Romney. Now he is considering running in 2016. I tend to agree with Larison that this is probably good news for non-interventionists. Bolton is a near caricature of the hysterical hawk, and will hopefully help make hyper-hawkishness look silly. He may also take a few votes from the other hawks who are less single issue (Santorum, Rubio). There is a risk that he will drive the other hawks in the race in his direction rhetorically, but it’s also possible that he might poison that space and make the others less likely to want to join him.
Those are my practical considerations. More viscerally I hope he runs because I think it is useful when people run from outside the normal path. If everyone who runs has to be a Governor or a Senator then that narrows the field to a group that is already too politically compromised to be of much use. People who are concerned with opposing the Establishment should encourage these sort of Quixotic campaigns by non-traditional candidates. A hyper-interventionist like Bolton might open up space for a non-traditional non-interventionist. As of now, I don’t see any non-interventionists considering a run. (I don’t consider Rand Paul ideal on foreign policy.) If we are going to be represented it will likely be by a non-traditional candidate so it doesn’t do non-interventionists any good to mock Bolton on the grounds that he is non-traditional.