I'd take issue with the bolded part of that assertion. Palin endorsed Mourdock. He lost. She endorsed Christine O'Donnell. She lost. She endorsed Sharron Angle. She lost. Palin is enormously influential in GOP primaries. But she doesn't get Republicans elected in place of Democrats.
Might want to ask Ted Cruz, Nikki Haley, Marco Rubio, John McCain, Terry Branstad, Jason Smith, Martha Zoller and a bunch of other people about that...
Shocker From ABC’s Jonathan Karl: ‘Sarah Palin Is 4 for 4 on Her Senate Endorsements’
http://www.freerepublic.com/focus/f-news/2914954/posts
Palin is the most effective endorser in history, you didn’t even make an effort to name challengers to that title.
You merely mentioned some who didn’t win from among her 80 or so endorsements, she has done more to shape the Congress Senate, and Governorships in her own image, than anyone in history, also.
By the way, she didn’t endorse Angle in the primary and 2010 was a stunning victory for her and conservatism, it was history making.