Obama's comments on the right of women to unlimited abortion are more than simply political, though obviously there is a lot of political appeal to women voters in his commitment. I sense in Obama a deep commitment based on personal experience. I believe that, as a young man, he probably had a girl friend with whom he initiated a pregnancy that was unwanted by him and was ended. Why do I believe this? I look at two matters.
First is his campaign remark, speaking of his daughters, "if they make a mistake, I don't want them punished with a baby." He could easily have put his commitment to abortion of unwanted babies in general terms, without mentioning his daughters and without the moral term, punished, to describe an unwanted baby.
Second, though abortion is a right for women, interviews with women indicate that most women have abortions, not because they want them, but because men in their lives want them to have an abortion. In other words, abortion is a right for men that men largely exercise. This situation clearly fits Obama's remarks, where he is speaking as a man, his daughter's father, saying (as I read the comment's context) that he would want them to have an abortion if they became pregnant as unmarried minors.
What is the source of emotion behind these comments? The most likely source, easiest to hypothesize, is that, when he was a young man, a woman with whom he was having sex became pregnant. If she would not have had an abortion, he would face choices that could negatively influence his ambitions. He might have been forced into an unwanted marriage, or, if he rejected both marriage and the child, his future public reputation might have been damaged. So, presumably, an abortion was done and he was freed of choices and responsibilities he did not want.
As I said, this is all conjecture; but it is only conjecture that Obama was all too human. All too human: he raised what was convenient for him to a moral right.