Bias and poll prefacing

Something I've noticed on NBC, particularly the Today Show. I haven't done enough study of this to conclude definitively on this issue, but there seems to be a liberal bias present in the way that the results of close polls are reported. On a number of occasions, when a Republican candidate is in the lead, words such as "but it is still within the margin of error" or "it's essentially a dead heat" are used to preface the results. But, when a Democrat is in the lead, the wording changes to "he has a narrow lead" or "he is winning" are used ("he" referring to the Democratic candidate).

It seems to me that NBC tries, or at least tries really hard to LOOK like they are trying, to report un-biased, so I am wondering how CBS and ABC fare on this issue of poll prefacing.

What is even more disturbing to me (and this is nothing new) is the prefacing that is done with more substantive issues. For example, the recent CBS interviews with Palin. At particular points, it seems clear that her answers were lacking, but when asked which newspapers she regularly reads, CBS and others concluded that since she failed to mention one, therefore, she must read none. What a strange conclusion, though.

Bias, whether it is conservative or liberal, bothers me. It bothers me because I care about knowing the truth.

UPDATE 10-6-08: This morning on the Today show, Chuck Todd reported Obama as having around a 4-8 point lead in certain states/polls. On a previous occasion several weeks ago when McCain had the same lead in a particular state/poll it was described as within the margin of error. I'll just wait and see.

UPDATE 10-7-08: Today reports 48% to 46% Obama "in the lead" in national poll.