Why is the press like a sheep behind a wheel?

When a traffic lane is closed, there is always some asshole who doesn't merge in an orderly way, but keeps driving in the emptied lane until it really ends, and then butts in. When that happens, I am not mad at the asshole, but at the sheep that lets him in. Looks like Dean Baker shares my sentiment, with a slight modification: the assholes are politicians and the sheep are the journalists.