A combination of logical disconnect and creative writing...
Every individual is flawed - some more than others. In Romney's case, he is hopelessly flawed when it comes to politics. However, even this man has done some remarkable things. I don't see the need to lie about his past in order to break him down even more. Let his political record stand for itself. But painting John McCain as some pro-life saint for the purpose of drawing a contrast with Romney is purely disgusting.
Romney has done remarkable work at Bain and Bain Capital which has affected hundreds of thousands of lives in a positive way. He has effectively been a physician for dying businesses. And that is a far better record than the vast majority of politicians occupying Washington these days.
btw, when polled about possible GOP Presidential candidates for 2012, I always say 'someone else'. Got any ideas?