I snicker at people who count Sarah out at this stage and I do not have any problem with her evolving position on the birth certificate issue.
If she had she been the one to try to force the question months back, it would have definitely killed any chances she would have in the future. She would have gotten no traction, no respect, everyone would have laughed at or ignored her and it would have further delegitimatized the entire issue.
Choosing which battles to fight is something every canny politician has to do. Sarah looked at the cards she had and decided that it was not a good time for her to weigh in.
To my mind, Trump is the perfect foil for this. He can’t be bought, he can’t be ignored and he’s impossible to scare. Fine, let him take point for a while.