First of all, CBS screwed up and has to take responsibility. Unfortunately, Fox is not the best. In fact, it is considered a joke in teh industry. They have never been an objective new source and its owner is a theocratic hypocrite who airs the worst crap on TV and lectures about morality at the same time. Fox is known throughout the industry as being the most biased news source of them all. Unfortunately, with the advent of 24/7 news, news stations do not have the opportunity to authenticate or analyze every news item as carefully as they used to... they are now reporting live and in real time, and have no time to thoroughly check info. In fact, most reporters throughout and especially in this war say they do the best they can given the time resources.
Last, it is funny you mentioned mudslinging as Democrats on the federal level historically have not gotten into the mud pit on the same level as the Repubs. Typically, Repubs see campaigns as something to win regardless of tactics. Depending on who you talk to, Dems lack the cojones or ruthlessness to combat here.
Last, it is hilarious you judge Kerry when Bush has the biggest, best known pit bull of a campaign fighter on his side. Karl Rove is notorious in Washington for being the most ruthless, unethical mudslinger in politics. In his view, nothing is below the belt and truth is just irrelevant to winning.
As an example, when John McCain was running in another election, Rove was hired by his opponent and started a whisper campaign in the deep South alleging that John had a secret Black love child. In truth, McCain and his wife have adopted children of various ethnicities. Rove purposely misrepresented the truth in a racist demographic and has initiated various other campaigns in the same fashion.
Rove runs the campaign and sets the tone... Bush continually plays ignorant.