Teresa Sharp is fifty-three years old and has lived in a modest single-family house on Millsdale Street, in a suburb of Cincinnati, for nearly thirty-three years. A lifelong Democrat, she has voted in every Presidential election since she turned eighteen. So she was agitated when an official summons from the Hamilton County Board of Elections arrived in the mail last month. Hamilton County, which includes Cincinnati, is one of the most populous regions of the most fiercely contested state in the 2012 election. No Republican candidate has ever won the Presidency without carrying Ohio, and recent polls show Barack Obama and Mitt Romney almost even in the state. Every vote may matter, including those cast by the seven members of the Sharp family--Teresa, her husband, four grown children, and an elderly aunt--living in the Millsdale Street house.