Former Alaska governor and one-time Republican vice presidential nominee Sarah Palin has been an active player in primaries across the country during this midterm election year.
She has endorsed Republican candidates in many races -- some well-known, some not so familiar. Some have been Tea Party-supported candidates, and others more conventional Republicans.
And so far, she has picked far more winners than losers -- scoring particularly well in Tuesday's races.
If Palin is a polarizing figure among voters as a whole, that is not the case when the focus is limited to just Republicans.
According to a recent Washington Post poll, only 37 percent of Americans say they have a favorable impression of Palin. But among Republicans, that number jumps to 66 percent. And that is what makes a Palin endorsement a big deal to candidates in GOP primaries.
Last month, Palin gave her seal of approval to South Carolina gubernatorial hopeful Nikki Haley. At a rally in Columbia, Palin said she came to give a "shout-out to a strong pro-family, pro-life, pro-Second Amendment, pro-development, conservative reformer."
The cheers of that day were followed by a big boost in name recognition for Haley, who was battling to get attention in a crowded field of candidates. Weeks later, Palin again helped out by sticking by Haley when allegations of marital infidelity threatened to derail her campaign.
While Haley didn't quite manage to avoid a runoff election in Tuesday's primary, she did finish first by a wide margin.
Palin has often looked for female candidates to endorse -- "mama grizzlies," as she put it in a speech last month to the conservative Susan B. Anthony List in Washington.
"You thought pit bulls were tough? Well, you don't want to mess with the mama grizzlies. And I think there are a whole lot of those in this room," she said.
One of the so-called mama grizzlies Palin endorsed that day was Carly Fiorina, who won Tuesday's Republican Senate primary in California. Palin chose the former Hewlett-Packard CEO over a Tea Party candidate.
But Palin doesn't always make her choice known in a big speech. Sometimes she makes an announcement via Twitter or other social media -- and sometimes that happens just days, or even hours, before a primary.
Last week, Iowa gubernatorial candidate Terry Branstad was at a small campaign event when someone handed him a note.
"I never expected this," he said, reading the paper. "Sarah Palin just endorsed us on Facebook."
Branstad, who served as Iowa's governor from 1983 to 1999, didn't need the backing of Palin to clinch victory. At the time, he already enjoyed a double-digit lead in polls. He went on to win Tuesday's primary in a landslide, beating a strong social conservative who may have seemed a more likely ideological choice for Palin.
If Branstad wins the governorship in the fall, he will be an important player when GOP presidential hopefuls start visiting the state in advance of the 2012 Iowa caucuses.
On Tuesday, there was a loss for Palin in Arkansas. She picked an underdog, State Sen. Cecile Bledsoe, in a runoff election in the state's 3rd Congressional District.
There have been other defeats this year, but mostly it's been success for Palin picks. Republican political strategist Mark McKinnon says candidates have noticed.
"She's having a huge impact," McKinnon says, adding that "in today's political environment, endorsements mean less and less, and hers seem to mean more and more."
McKinnon says Palin is challenging her own core supporters with some of the endorsements she's made. When she backed Fiorina in the California Senate primary, for example, Palin's Facebook page lit up with complaints that Fiorina isn't conservative enough.
Palin countered that Fiorina opposes abortion, supports gun rights and, compared with the rest of California, is indeed a conservative.
" I don't think six months ago Sarah Palin would have endorsed Carly Fiorina," McKinnon says. "And I think that today she recognizes that by doing that, it just gives her a broader platform, more power and more influence."
McKinnon says Palin knows something else: that it's important to back winners.
Of course, all of this is playing out in Republican primaries, where Palin is a popular figure. Things will get much more complicated as the general election in November approaches.