Remember, Trump lost the popular vote by a couple million, in an election where about half the country voted, so his base in general could be estimated at about a fourth to a fifth of the country. But if we take the "more than 5 to 1" figure from the linked article as valid, then it implies that even a bunch of people who voted for Trump liked the accord. My impression is that people didn't like Trump for policies having to do with the environment or climate change- they liked his stance on immigration and general outsider status.

The not-being-responsible-for-other-countries bit is also a popular policy of his (arguably, its his most widely-appealing position altogether), but I'm confused that you think that that applies to the Paris accord. The accord didn't mandate us giving anyone else anything, and climate change is going to mess the U.S. up as much as anywhere else.