I once had to take a graduate level course in social psychology from a rabid Marxist professor.  One of the things taught was the following: If you force people to do something even though they don't want to they will generally make excuses later and accept it as ok.  If they can't change their behavior due to force, then they will change their thinking.  This is what underlies the Stockholm syndrome, brainwashing, and much of the left's forcing us to do things we don't want to do.