^ I would say there should be majority support in
1)any place with zone 1A commuter rail fares (or that could be incentivised by offering to put them in zone 1A)
2) any place where a majority of CBD bound commuters today go by bus or bus-rail, so Everett Chelsea Winthrop Revere.
I would expect Weston, Lincoln, Lexington and Milton to be initially skeptical, since they drive a lot but would not trust the predictions of how much faster their car commute could be if the core were uncongested. I would think they would come to support it after implementation because the value of the time they save is likely several times the charge they'd pay.
Two big faulty assumptions here. First is the class warfare angle. Somehow the high money people with $$$ to burn would care about paying 2 more bucks a trip, but the low income people would have a smile on their face about taking a much more meaningful bite out of their paychecks. The second is that this would actually reduce traffic in a noticeable way. With increased population growth that's a dubious assumption.
Recall when the state tried to index the gas tax. Putting aside our own personal view of the merits of that proposal, it got recalled. Same thing would happen here, based on factual evidence of recent history.