Palin's endorsements are "probably equivalent to Oprah's in the short term," but it's too soon to tell how powerful her endorsements have been, said Madeleine May Kunin, Vermont's first female governor and author of "Pearls, Politics, & Power: How Women Can Win and Lead."
"I don't know if its her endorsement as much as her visibility as a different kind of female politician than we've traditionally seen," Kunin told ABC News. "Primaries often are won by people who get dedicated supporters. There's no doubt she has wide appeal but I don't think we've tested yet how wide that is, whether it will pause up to the general election."
Others say endorsements only make a difference when there is a specific block of voters the endorser can bring in.
"The only time that they really make a difference is when they are truly unexpected and someone turns on somebody else," said Republican strategist Alex Vogel. "I don't believe that Governor Palin has a specific block of votes that 'Hey, you get the Palin endorsement,' and there's an extra hundred thousand people who are coming out for you."
The biggest impact Palin's endorsements have had is perhaps on herself, helping to keep her in the spotlight as questions swirl about her future political moves. Every win has helped raise Palin's own profile and established her credibility and influence on voters.
"In a way the biggest impact that she has had has been through these endorsements. She no longer has any real political perch from which to do anything other than as this endorser-in-chief. It allows her to make news that's political," Vogel said.
While Palin's endorsements have probably garnered more attention, Republican heavyweights like Romney, Minnesota Gov. Tim Pawlenty and former Arkansas Gov. Mike Huckabee have also been quietly making inroads in key campaign states. Pawlenty has established a political action committee to raise money for GOP candidates in Iowa and New Hampshire, important battlegrounds for presidential candidates. Romney and Huckabee have also been building their own brands in national races.
But it's Palin's "non-traditional political operation" that has baffled the Republican establishment -- many times her endorsements don't involve any donations and are announced through social network sites. She also hasn't shied away from "going rogue" against the Republican party.
"She's definitely one of the first people on such a prominent scale to take advantage of new media to push her message," Soltis said. "You really have removed the filter between a public figure and the public with tools like Facebook. It's definitely new. It's a far cry from the traditional image of an endorsement."
Palin is also one of the few GOP leaders who have used endorsements to advance Republican women candidates, and has built a group of supporters around herself in key parts of the country.
This "is another way for her to build a coalition and to differentiate herself from her potential rivals, whether it's for future political office or just for some of the political limelight," Vogel said.
Whether Palin pursues a presidential run in 2012 remains unknown, but she will likely remain in the spotlight and continue to coalesce around women candidates in the November midterm elections.