There were things we all did as teens that went against our parents teachings. All of us. Every one of us got in trouble with our parents as teens. We would not have been in trouble with our parents if we had followed their teachings to the letter. Just because we got in trouble does not reflect poorly on our parents, it reflects poorly on us because we were the ones making the decisions that got us in trouble in the first place. (Disclaimer: there are some parents that don't actually do any parenting and their children's actions DO reflect poorly on them.)
There comes a time in every child's life where a parent has to trust them to do what is right. It is part of the process of growing up for each of us. Sometimes our children are going to make decisions that are not in their best interests, sometimes the consequences of those decisions are lifelong, as is the case when a teen gets pregnant.
True, most children do do things that are against their parents wishes. I, however, maintain that the big things (going to prison, getting pregnant) are things that reflect very poorly on the parents, and are things that could have been avoided with better parenting.
These things aren't evil, and don't make the parents evil. That said, when you are trying to be the next Vice President, things like this are definitely representative of your ability to do your job. Personal matters such as this will be, and should be, examined by the people which you hope to represent.