You assume these people care about "what is good for the people." Like CNN and MSNBC, claiming "R's say this, D's say this, I can't tell what the truth is!"
There is the record, there is history. One party is aligned with their corporate donors more than the other. While both have issues, on issues involving corporate power and influence, R's are clearly on the side of corporations and wealthy donors who keep them in power.
EDIT: there is no need for being fair because everyone else does this, but many times, D's end up being "republican-lite" because they believe it will appeal to R's and also appeal to their (the D's) donors; but there is no question as to which side the R's lie on.