Left leaning? I think it was Colbert that put it best - reality is left leaning.
Maybe there was some bias I am not sure but it seems to me that both left and right see bias in newscasts.
I find it funny when I hear some conservatives call other elected Americans Marxists and things or members of the far left - there is no one really in the far left in mainstream American politics but I'd say Ron Paul may well be. The political compass seems to think so but maybe this is left-wing propaganda to make him seem extremist/radical.
View the 2008 US Election
Here's Canada
The Conservative Party of Canada being in between Republican and Democrat but probably closer to the Republicans, and our Liberals being to the left part of the Democrats.