by Angelo Muredda An incendiary political missive in search of a good movie, Finding North is as frustrating as it is revelatory. Directors Lori Silverbush and Kristi Jacobson come at the problem of hunger in the United States with the statistical acumen of seasoned journalists. Their conceptual scope is expansive, covering everything from the daily struggles of Rosie, a seriously malnourished fifth grader, and Barbie, a single mother of two, to more abstract problems like the federal government’s complicated dance around subsidies for enormous agribusinesses at the expense of local farmers. With the help of some unexpectedly poignant commentary from celebrity…