It's not the number 71, the percentage of Americans who consider Sarah Palin unqualified for the presidency.
It's 52, the percentage of Republicans who think she is qualified for the presidency.
If only a smidgen more than half of your own party thinks you could hack the job at all -- before other factors (candidates offering superior qualifications, how the contenders match up against the other parties' nominees, etc.) even come into it -- a brutal reconsideration of your aspirations, in the cold light of reality, is probably very much in order.
The spin on this should be interesting -- check it out at memeorandum.