Faithful NPR (specifically my local branch) listener here. I agree with your general point, though I notice it most with immigration related stories. The thing I appreciate about how NPR covers things though is that their commentators are almost never spokespeople/PR reps. They are legit professionals in the field, elected officials, or people who seriously study this subject matter. Of course they still have bias, but not _nearly_ as much as what I hear / see in other media which is "person whose literal/only job is to promote political stance X."