An HBO documentary produced by Ed Norton, By The People:The Election of Barack Obama (9pm on Tuesday HBO 6pm Friday 3pm Sunday tells the backstory to the election of the nation’s first black president through the eyes of four key volunteers in the grueling on-the-ground campaign where votes are earned one at a time. One of the campaign warriors is Michael Blake, who’s path to the White House involves a key element of fully realizing Opportunity: giving back, in his case, through public service.