Sarah Palin reasons through each issue:
1) while asking herself "What is the right thing to do?", and
2) while being committed to having nothing to hide.
"Professional" politicians, at core, usually think this:
The electorate is stupid; we must lie to them for their own good.
Media consistently ask questions which are founded on false premises. It's difficult and wearying to constantly shoot down the stream of kamikaze false premise questions flying at you. The alternative is to play along with the false premise questions, i.e. to give couched and inauthentic answers which the devious media and the "stupid electorate" will accept.
Sarah Palin has, so far, refused to go down this path. Such is more difficult, yet also more respectful of the electorate. The benefit is Sarah can be relaxed and quick and easy in her answers. She only has to remember the truth. The risk is she will slip: she will respond to false premise questions in ways which can be spun as scandals.
Remembering postures and lies is Hillary Clinton's problem. It's hella-difficult for Hillary to fully recall her postures and lies. When responding in conversation, Hillary hesitates just enough for viewers to intuit that she is not open and genuine.
Sarah Palin doesn't hesitate. She bursts forth.
Maybe she doesn't have time to hesitate - chica has things to do! Trig needs changing; Piper's hamminess needs corralling; that natural gas pipeline needs shepherding.
Speaking of shepherding - please, Sarah - for the sake of all that is holy: please trim the bangs!