Notice that the greatest differential in the candidates' vote percentage between the New York and the New England side of the border follows the crest of the Taconic Mountains, and the least differential exists on either side of Lake Champlain.
I'm not sure what category of people or geographies "Birkenstock" is meant to signify, other than a vague association with the prevalence of liberals in rural Northwest New England. It is not the best term to describe a blue-collar city with a manufacturing pedigree such as Pittsfield, for example, which happens to be the largest city or town in the "Belt" in Torie's map. Rather, as Averroës alluded, it's a diverse region, taken as a whole. Within the so-called belt are old mill-towns, resort communities, college towns and their periphery, and remote rural communities with weak historical or cultural connections to any of the above. It's just too simplistic to apply a label like that to an area with multiple currents of political culture. Perhaps "GOP Estrangement Zone" is a bit clunkier, but it's surely more apt.
Yeah, I tend to agree. The region is definitely interesting and worth studying politically, but Torie's analysis is a bit too simplistic.