It's obvious, my opinion, and backed by data.

That's all interesting, but it doesn't really address the point that NPR's coverage is biased by a desire to please its audience. Even though tautologically true for all organizations, it is disingenuous to suggest (as GP is doing) that NPR gets to don a mantle of impartiality because they don't run (some) ads to finance their operation. Despite how hard "NPR has tried to avoid this".

So, sure, pick your favorite partisan news source. But don't try to claim that it's unbiased because it doesn't generate revenue with ads.