I am looking for the author of the quote in title. The phrasing might not be exactly as quoted, but the idea behind it is that the right wing politics are usually aiming to go back to certain period in time which they consider to be the ideal one. Like if to get better as a society we need to undo the changes that led us here and go back to this previous ideal society. Whereas the left thinks that the ideal society has never really been implemented yet, so we need more changes in order to get there. I've heard during college, but the teacher is sadly retired due to health issues.