I think you are mixing two different ideas. If you think Sarah quiting her first term will hurt her politicaly, fine.
If you think Sarah is quitting because she is tired of politics or there is some hidden scandal and her political career is over, then you haven't heard her full comments that she made today.
I believe she is keen on running in 2012 and I believe she thinks that today's decision will free her up to pursue that goal.
I think she’s about to open a can of whoop ass on Zero.
Can she not say that she stayed in office longer than he did before running?