Check out Gov. Romney's reasoning:
According to the FDA, the pill mostly works by stopping the release of an egg from the ovary. But it also may block fertilization or prevent a fertilized egg from attaching to the womb. For those who believe life begins at conception, that amounts to abortion.
Supporters of the Massachusetts law say the governor broke his word by vetoing it. On a questionnaire abortion rights groups gave to the gubernatorial candidates in 2002, Romney answered ''yes" to the question, ''Will you support efforts to increase access to emergency contraception?"
But Romney, who describes himself as ''pro-life," said he had to veto the bill to fulfill a campaign promise not to change the state's abortion laws. Because the Massachusetts bill does not have an age restriction and Plan B sometimes causes an abortion, Romney argued, the measure undermines the state's parental consent laws.