In my anecdotal experience, backed by polls, working NYers did support the strike: Blacks and Latinos, over-rep'd in the working-class and poor of NY overwhelmingly supported the strike while whites did not. "two cities"
other unions did show support. They were overwhelmingly in support of the strike and were at all the rallies leading up to it: PSC, SEIU,and others were very visibly out in support on the picket lines, which all of our unions attended. Unfortunately, because the strike was a surprise to most of us, most unions - including the TWU - were not ready with an on-the-ground 'educate the public" solidarity campaign.