Tina Fey claims her 2008 impression of Sarah Palin did not help her show 30 Rock. While the comedian climbed the ranks doing her impression of Palin and helping President Obama win the presidency, she believed it helped sink her chances on the show.
The show, 30 Rock, was not doing well, and producers thought that Fey's new found fame would carry over to the show, but people just couldn't see her in another role. Fey believes that many Americans believe she and Alec Baldwin are perceived as communists, and that is also why the show is floundering.
Sarah Palin probably has a larger following of fans than either Tina Fey or Alec Baldwin. Fey's attacks on Palin and her family were novel and funny at the time, but it did not carry over to her floundering show. She had a hot topic with Sarah Palin. It was Sarah Palin who interested people to watch SNL, and Fey temporarily benefited from that with good writing and her doppelganger looks. Tina Fey is just not that funny nor is 30 Rock, but NBC has picked up the show for another season.