If the writers and actors don't know anything about Republicans...
except what they've heard from the stereotypes, how could they possibly portray one accurately? They have to actually get to know some Republicans and do some research. As it is, just about every portrayal of a Republican in recent memory is based on ignorance. By and large, Republicans are portrayed as bigots who are trying to force their narrow-minded religious views on everyone. For examples, see "The American President", "West Wing", "Commander in Chief" as starting points.
I'd be surprised if any of the writers of those shows has ever held a real conversation with a Republican in years, if ever. It sure comes across that way.