I would assume no political candidate travels w a SM, rather that they work w the PM/SM wherever they go - seems to me this is more likely a case of the venue rather than the people.
Otherwise, it is probably like all convention/industrial work, so you need to get into that circuit. If you have a convention center near you, contact them for their resident TD/production manager and start talking to the SMs who come thru w the various conventions and events.