Calling it "the other side" is a false dichotomy. There's certainly advocacy groups like Sea Shepherd but they don't wear cloaks of subterfuge to try to distance themselves from their structure and purpose like say, the heartland institute which among other things, was, at the time secretly, funded by Philip Morris to deny that smoking had health impacts.
That's a different class of spin. But sure, the Brookings institution is mostly neoliberal radical centrist, fine.
They are however, vast majority, on the right side of the spectrum and all the various flavors of right https://en.m.wikipedia.org/wiki/List_of_think_tanks_in_the_U...