Left leaning sure, but i have heard them blast people on the left plenty of times. If you listen to them regularly you would see that. The problem with most on the right is they hear one news outlet say something negative about the right and they turn off the channel and assume they are all on a right wing bashing spree. NPR is not this way in the least bit. This is coming from a republican.
With NPR it's entirely possibly that your commute in the morning is different content than mine. I can't possibly listen to them all day but I know one thing for sure. In general, they have positions on topics and they run that INTO the ground basically assuming everyone must agree with it. Then it becomes part of their narrative. They are very picky when to put on dissenting voices. Often times when they are needed, you get none. And NPR is horrible to Trump when they'd get respect if they'd buck the trend of the rest of media.