Like others, I didn't notice it until this presidential election cycle. Used to be a huge fan and financial supporter of NPR but that undid it for me.
It's a bummer because there was, and still is, a lot of good content on there but I'm disappointed at their bias, I thought they were better than that.
I haven't really found a solid replacement for them, it's a little here and a little there and more research on my part.