“So is it that we’re biased and therefore we go to the site that agrees with our bias or are we biased because the site that we usually go to feeds us biased information”
I think it’s a combination.
There’s also almost a feeling of intimidation to agree with the “other” side of whatever side you are on.
Meaning, if you are a bit more conservative and you read CNN then you might feel that you must plug your nose. If you tend to identify more along the left then even when you agree with Trump, as a CNN commentator did yesterday, it must be with a huge “but”.