CHARLESTON, S.C. -- On June 3, 2010, a phone rang at the campaign headquarters of Iowa gubernatorial candidate Terry Branstad.
Leo Hough, a receptionist, picked up and was greeted by a familiar voice. It was Sarah Palin, calling to let the campaign know that she was about to endorse Branstad on Facebook and Twitter.
There had been no previous discussions between the former Alaska governor and the candidate, who was as pleasantly surprised as everyone else when told the news.
That episode is typical of how Palin has made endorsements: suddenly, independently and without fanfare.
After leaving an indelible mark on the 2010 midterm elections, Palin has had a minimal impact thus far in this cycle. But one presidential candidate is hoping that the Mama Grizzly is about to come out of hibernation.
Despite the deeply held maxim that endorsements are overrated, Newt Gingrich and his senior aides are increasingly hopeful of gaining Palin's support, which could mark a significant turn in the Republican nominating fight.
In a Fox News appearance on Tuesday night,but told Sean Hannity that if she were a South Carolina resident, she would vote for him "in order to keep this thing going."
Palin's husband, Todd, endorsed Gingrich earlier this month, and top Palin aides have told RCP that both members of Alaska's most famous political couple speak favorably of the former House speaker in private.
In a Washington Post poll released last week, 23 percent of registered Republicans and GOP-leaning independents nationwide said that an endorsement by Palin would make them more likely to back a particular candidate, while 15 percent said it would make them less likely to do so.
But Palin's impact among evangelical and Tea Party-leaning GOP voters could be significant in the current multi-conservative field.
Asked how impactful a Palin endorsement would be, one Gingrich aide replied succinctly: "Big."
The former Georgia congressman has done nothing to mask his delight at the prospect of securing the nod. He told Politico on Tuesday night that he spoke to Todd Palin after his wife's most recent comment and was "thrilled" by what she had said, touting it as a "signal" to conservatives to rally around his candidacy.
Without a direct line to his former Fox News colleague, Gingrich and his team can only hope that her husband's unambiguous show of support is a precursor of what is to come.
And there's precedent to believe that will be the case: In the spring of 2010, Todd Palin endorsed Joe Miller in his primary fight against Lisa Murkowski a full month before his wife did the same.
"Neither Todd's endorsement nor Sarah's kind words on 'Hannity' came with warning," said another Gingrich aide. "But that only makes the gestures genuine. Less political."
One close Palin aide was skeptical that Palin is preparing to endorse Gingrich, telling RCP that there have been "no internal discussions" about it.
Still, the same aide noted that Palin's "South Carolina endorsement" of Gingrich on Fox News had not been previously discussed among her inner circle and that the former Alaska governor is always liable to live up to the "rogue" persona that she so cherishes.
If Mitt Romney is able to hold on to his lead in South Carolina and deliver a commanding win on Saturday, Palin may be less inclined to go out on a limb for Gingrich, who has suggested that he needs a victory here to remain viable.
But if Gingrich pulls off the upset, or comes close to doing so, her potential to impact the race going forward will grow significantly.
Palin's influence could be deeply felt in Florida, the next state on the GOP calendar, where free media holds immense sway in a large and expensive primary state that is closed to non-Republican voters.
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