With polls showing that Republican Mitt Romney has significantly eroded President Obama's once-robust lead among women, both parties have turned their attention in the final days of the 2012 campaign to a key slice of the women's vote that could be crucial to victory - millions of potential "Obama defectors." Women who voted for the Democrat in 2008, and are considering jumping ship this year, are a target of impassioned campaigning as Republicans and Democrats aim for the margins in battleground states. Nancy Keenan, who heads NARAL Pro-Choice America, the nation's largest reproductive-rights advocacy group, said Monday that her organization...