For the folk at opposing ends of the abortion issue in the United States, the fight is a matter of life and death - pitting an unborn child's right to life against the mother's right to choose the life she seeks. The backstory is fascinating for the light it sheds on America, a nation both secular and religious, a closely watched arena for battles to expand protection of women's rights, and a complex union with both state and federal law, over which presides a Supreme Court that is both guardian and interpreter of the US Constitution - yet, whose makeup is shaped by partisan politics.

In 1973, the Supreme Court ruled in a landmark case, Roe v Wade, that unduly restrictive state regulation of abortion is unconstitutional.