Romney would choose a woman if he did run and win the nomination.
But he didn't last time, why would he do it this time?
Palin.
I reject this explanation. The reason he didn't pick one last time was because there were no qualified female candidates, so picking a woman would make it obvious that he was picking someone unqualified
just so he could have a woman.
Why the situation was that way in 2012 is due to a fundamental problem with the Republican Party. It doesn't get much better in 2016, but there will at least be a couple of two-term governors (who happen to also be minorities), so it will be possible to pick a qualified woman then.