Left-wing garbage in, left-wing garbage out
At the same time, studies which contradict political orthodoxy are subjected to a level of criticism which inevitably fulfills its objective of finding some far less serious flaw to serve as a basis of loud and resounding rejection. Science has to an unconscionable extent ceased to be science and become propaganda, while peeer review has become an arena not for the objective analysis of methodology but for the discrediting of political heresy.
As a result, the very source of science's authority- its laser-like focus on the facts precisely regardless of our personal attitudes and prejudices- has been subverted. It's fasciating, for example, that according to current theory there are (not insurmountable) developmental problems associated with growing up in a home without an opposite-sex parent- unless both of one's parents are gay! The same is true of studies in various other sciences, both "hard" and "soft."
Gene Veith has a good post on the problem of phony and non-reproducible results from Left-leaning psychological and sociological studies. As I've said many times, the faith of people who actually think about such things rather than exhibiting a sheeplike acceptance of whatever "authority" tells them in science is under severe challenge from the amount of propaganda masquerading as science these days- and obligingly accepted as such by the media.