Republican primary voters like macho candidates and no one is more macho than Sarah Palin.
In a way the fashionista and mother of five evokes more toughness than any man regularly mentioned as a possible presidential candidate in the GOP. Palin is visceral, in your face, relishes combat, and won't be shamed. (Her hobbies include ice fishing, snowmobiling, running, and hunting.) These are traits usually and stereotypically associated with men - and they're especially endearing to Republicans, who like to see President Obama hit with the most force possible.
The basis of her popularity says nothing about whether she will or won't run for president or even if she could win. It does show that she's passing the Republican test of who is the toughest person on Democrats and Obama. It's a "macho primary" of sorts.
Palin goes after Obama at every opportunity and hits him hard. She doesn't use a politician's favorite tactic of saying at least one nice thing about the opponent's character before shredding a man's past, questioning his judgment, beliefs, and priorities. Palin shows as much mercy as Jack Bauer.
Not only is Palin tough on Democrats, she seems to genuinely enjoy beating them up. Crowds get behind Palin's attacks of Obama because she makes being mean fun by using humiliation, sarcasm, cutesy catchphrases, and smiles.
Republicans know she won't bow to what they think are elite sensitivities or political correctness. Say she was "going rogue" as a diss? She'll make it the title of her book. Dismiss the GOP as the "party of no?" Palin will rename it "the party of hell no!" Argue that her slogan, "Don't Retreat, Instead RELOAD" is a call to violence? She'll repeat it and then add "that is not a call for violence."
In 2008, John McCain was tough but not merciless on Obama. If he got energized by crowds, it was because he was ad libing and going back-and-forth with questioners--not because they were cheering his peroration. (Palin doesn't really take questions.) McCain occasionally took his party to task for outrageous rhetoric. Even this modicum of restraint left Republicans dejected -- until the pit bull with lipstick came aboard and started mauling Obama.
Who else is as macho as Palin? Tim Pawlenty? Too nice. Mitt Romney? No fun. Plenty of Republicans refuse to apologize, but none appropriate negative accusations quite like Palin does.
The last person to be loved by Republicans as much or more than Palin was George W. Bush. While he can't run for president again, another Texas governor full of swagger could run and do very well in the macho primary: Rick Perry.
Perry campaigned as a Tea Partier in everything but name during the Texas Republican primary this year. He used anti-Washington, right-wing rhetoric as hot as anything Palin has said--and went on to demolish Kay Bailey Hutchinson (he'll win the general election). Get a taste of the rhetoric and see how much Perry gets fired-up going after Washington here.
Republicans don't want a passionate reformer or soothing reconciler--they want a fighter.