NPR gets a substantial part of its funding from the government (through the Corporation for Public Broadcasting) and from various corporations that act as "underwriters."
With respect to the first source, over the years whenever NPR has run a story that has offended some right-wing congressman or interest group, there have been various calls to eliminate completely any federal funding for NPR.
Clearly, in view of these two funding sources, NPR is on a leash with respect to what it can say and the points of view it is allowed to present without getting into trouble. Basically, it cannot afford to step on too many toes.
I stopped taking NPR seriously over 12 years ago. However, I've noticed that over the past several years, the situtation has gotten a whole lot worse in terms of the "controlled" nature of NPR's content.
A prime example of this is the coverage of events leading up to the start of the current war with Iraq.
During that time, although NPR did acknowledge the presence of an anti-war movement, not once did I remember NPR ever interviewing a single activist or critic that said that Bush and the Administration were not being truthful or accurate in their claims about the need for war.
And I KNOW these voices were out there (e.g., Scott Ritter) because I was marching with them in the streets and I was learning about them through the Internet. (In fact, it is because of them that I was basically convinced by September of 2002 that Bush was LYING about Saddam, WMD, and Al Queda ties.)
NPR basically shut these voices out of the debate and its listeners basically received a one-sided view of the case that the Bush Administration and their confederates were using to convince the country that war with Iraq was necessary.
To learn more about what ailes NPR (and PBS as well) pick up a copy of David Barsamian's "The Decline and Fall of Public Broadcasting." (You can order a copy of this book through South End Press' website.)
In Barsamian's book you'll see the real nature of public broadcasting in this country and how it basically serves the interests and agendas of corporate/government/establishment points of view. You will learn how this situation is the result of the very way that Congress set up the funding mechanism for public broadcasting during the 1960s. As Barsamian makes clear, from its inception, public broadcasting in this country, as a result of NOT having a funding mechanism that is insulated from political influence, has always been on a fairly tight leash--which various politicians (starting with Nixon in the early 1970s) have yanked on whenever NPR or PBS started to step on some powerful toes.
Also, check out this study from Fairness and Accuracy in Media:
http://www.fair.org/extra/0405/npr-study.html
It's pretty damned enlightening in terms of who exactly the talking head/experts are that NPR relies on in its broadcasts, and to what degree NPR fails in its stated mission to give alternative voices a public forum.
Clearly, the biggest myth there is about our so called liberal media is that NPR is really "liberal."
On second thought, NPR is "liberal." However, if you really think about it, NPR's "liberalism" is largely confined to the following issues (and even here, less and less lately):
Gay rights
Abortion rights
Discrimination against women and minorities
Issues of Separation b/t church and state
Now, if you live in "red state" areas of the country, this type of liberalism is probably significant, and perhaps I'm wrong to underestimate its importance.
However, on the whole, if there is any "liberalism" on NPR it is a "limosine liberalism" that is largely confined to the "cultural" issues I listed. On every other issue--economics, power relationships, foreign policy, distribution of wealth, the fundamental assumptions that undergird our society, NPR largely follows the lead of establishment elites in corporations, think tanks funded by corporations, and the government.
I still listen to NPR. But I never send them a dime. Also, knowing where they come from allows me see their news coverage for what it is with respect to all its glaring blindspots, biases, and weaknesses. In short, knowing these things about NPR specifically and public broadcasting in general leads me to regard most of the news coverage I receive from these sources with a fundamental skepticism and helps me filter out much of the crap.
NPR has its use to me in that it allows me to fill the dead air in my car on my drive home from work. But these days, I get most of my real news and opinion via the Internet.
On the whole, NPR largely sucks.