英文Obama, the infomercial: A 30-minute pitch to AmericaStumbling upon a half-hour-long infomercial on American television is usually a sign that youve stayed up too late, or clicked too far through the channels to the outer fringes of cable. But last nights 30-minute broadcast happened in peak time, on three of the main networks, and it wasnt a sales pitch for an innovative new bathroom tile-cleaning device. It was Barack Obamas final opportunity to ask a mass national audience for thei