Carpetbagger's got a great post about The Dangers of Epistemic Closure, in which he describes the problem conservatives have when they only accept facts and opinions from like-minded conservatives, including the dismissal of conservatives who ever stray from what they want to hear. Basically, it's a garbage-in, garbage-out situation, and since they're fact-checking their garbage with more garbage, they only get more delusional with every passing day.
But of course, this doesn't only afflict people on the right, but is something everyone can fall victim to. If the only news you're willing to accept is news that already agrees with you, you're going to have a hard time dealing with the real world; which can often have things you don't want to hear in it.
And one major problem is that too many people suffer from an ad hominem mindset, in which they reject a piece of news if it comes from the wrong source. And even worse, they have a natural assumption of propaganda from any source that doesn't conform to what they want to hear; while they're too willing to accept news from a preferred source, without bothering to check if it's true.
Propaganda Isn't Always False
If the NY Times reports something negative about conservatives, then conservatives will naturally assume the Times has a hidden agenda and will dismiss the report. Similarly, if Fox News reports something negative about liberals, then liberals will assume that Fox has a hidden agenda and will dismiss the report.
Now, of course, Fox News is propaganda and does have a hidden agenda that isn't even well hidden, so it's understandable why someone would dismiss them as a news source. Yet all the same, facts are facts, and simply because Fox News reports something doesn't make it automatically false.
Similarly, the NY Times does have a liberal bias, in the sense that reality has a liberal bias and the NY Times reports reality. And so it's understandable that conservatives would dismiss this source because they so rarely report what conservatives want to hear. And whenever the Times reports something they want to hear (which happens far more often then they'll admit), they'll think "Oh, if the liberal NY Times says it, then it really must be true," even if it's not.
Just the Facts
And the problem is that any source can have truths and facts hidden in them, no matter how propagandic they are. And it's too easy to dismiss a fact, simply based upon its source. But that's something we must reject if we want to know the truth.
And the thing to do is to read news from all sources and really scour for the truth. To not accept information just because it came from Krugman, Kos, or Kuchinich; or reject something because it came from Fox or RedState. Only by doing independent research can we determine that "Obamacare" didn't have Death Panels, or that Obama's tax deal last month didn't defund Social Security.
Because it's not about who says the information, but what the information is; and even the most reliable source is only human and must be verified. And if anything, we must be more vigilant when reading news from an accepted news source; not less. And if you're not clicking through the links of your sources, and clicking through their links, and the links from those links, you might be getting deceived by someone who was themselves deceived. Everyone's human; including those we agree with.
Fact Check Thyself
And most of all, it's ourselves that we must be most vigilant about double-checking. It's easy to see when others are lying to us, but very difficult to see when we're lying to ourselves. Yes, you can have a working assumption that RedState is full of shit most of the time, but when it comes to fact checking, we should assume them to be more trustworthy than ourselves.
Only after triple-checking our own facts can we add it to the pile of information we use for other fact-checking. And if the only information you're willing to accept is the information that immediately confirms your own beliefs, then you probably don't know what you're talking about.
That's why I read Washington Monthly and TPM and other sources that report what conservatives are saying; while generally avoiding liberal sites that only report liberal news and opinions. And why I scour Yahoo News for stories of all types, while visiting sites like RedState. Many commenters at WaMo and TPM deride them for focusing too much on what conservatives say, insisting that we should be discussing liberal policies. But to me, that's exactly opposite. Because we already know our own facts and opinions. It's healthy to know what the other side is saying, just to make sure we're not missing something.
So I look towards outside sources in order to get as much information as possible, as well as engaging in any debate I can, while avoiding discussions with people who already agree with me; so as to not get caught in echo chambers and mutual admiration circle-jerks. And if you're dismissing a story solely because it was reported by a source you don't trust, then you can't possibly have any way of verifying your own beliefs.