I think we're wandering afield of Hobson's Landing, but I've long felt that Manchester (despite being the largest city in NH) and Nashua, even though they're both larger than Portland, are held back by their proximity and ease of access to Boston (they have I-93, we have Route 1 through Saugus). They feel more like satellite cities of Beantown than Portland does. It helps that we're the largest city in a state that stretches on for another 6 hours north, most of which is full of supernatural creatures and terrifying ghosts (or so the media tells me).