To be fair, of the 13 Republican candidates for whom Palin has stumped this year, several are appear to be cruising toward wins on Tuesday. They include South Carolina gubernatorial contender Nikki Haley (R), whose campaign took off after Palin endorsed her campaign.
But two of the candidates Palin stumped for in the primary season -- Georgia gubernatorial contender Karen Handel (R) and Idaho House hopeful Vaughn Ward (R) -- didn't make it through their primaries, when both were initially favored.
Because Palin invokes such loyalty from a small, conservative segment of the GOP, observers say her endorsement has become mainly helpful in primaries, but counterproductive in general elections where she tends to turn off moderate voters. Sabato compared her to Jesse Jackson on the left in the 1980s -- someone who was a valuable endorsement in the primary election but too polarizing in the general.
When Palin went to California recently for Republican rallies. Former Hewlett-Packard CEO Carly Fiorina (R), who is running for the Senate and has been endorsed by Palin, did not make an appearance at the events.
"She's controversial. She's a polarizer," Sabato said. "She's a classic case of a politician who can help a candidate a lot in a low turnout partisan primary, but generally costs votes in the higher turnout general election."