Sorry, while KBH has tons of great political experience, she is officially pro-choice which would have angered the very vocal and powerful Religious wing of the Republican party. Not so wise a choice politically.
Good point, yes the evangelical wing of the Republican party would have been alienated over that issue, and like it or not, they are needed for any Republican to win. Palin can pull a lot of HRC voters because even though she is pro-life, many of HRC voters are smart enough to realize Roe v Wade is unlikely to be overturned anytime soon, and also many of them I think were voting because they wanted to see a woman win. Hutchison would have pulled the HRC voters I think as well, but completely alienated the pro-lifers. That issue is extremely important to them.