At home in Belarus, and my time traveling and living in the Northeast and West Coast of the United States. I spend a lot of time in the political science part of libraries and I see it pretty commonly. Maybe not all small local libraries will carry it, but starting from a medium sized library, to large ones, its pretty common.
I have also never not seen Settlers in a university library, which are open to the public where I have been.
That sucks. Most of the university libraries I’ve been to have been pretty good at collecting a bunch of the more unheard of pamphlets and socialist works.
Granted, I was in the more left leaning areas of the United States.