You make a very good point about the democrats using Romney’s own words to attack McCain.
However, I think Romney’s likely performance between now and the election is the most most important factor to consider. The VP candidate must:
1) Have a very good grasp of the issues so that he/she can respond instantly and credibly to democratic attacks and hostile questions from the media. It doens’t matter as much to me that Romney has changed positions. I think it is more important that the VP candidate he be able to put the democrats and the media in their place quickly and decisively when necessary.
2) Must be able to win the debate. I think undecideds will watch the debate. Most undecideds in my view are heavily influenced by the debate performance and less so by past positions. Since they are less engaged, they tend to believe what the candidates are saying today, if it is said well and convincingly.
I readily admit that Romney is not ideal. The bottom line for me is that I think Romney will kick ass between now and the election and I am not sure about Palin. I am more concerned about what the VP nominee is able to actually do between now and November and less about ideal suitability. The reason I think that way is that I think performance between now and November is more important if we want to win. And the ultimate goal is to stop Obama.
And she will debate well. All she needs to know is where McCain stands and how wrong Obama's view is - and have a sense of humor. Huckabee won a lot of people over with his humor. Sometimes we lose perspective and don't realize there are no rules here. Reagan won with humor as well :-)