VIRGINIA'S ELEVENTH CONGRESSIONAL DISTRICT : One of northern Virginia's most seasoned political veterans -- —ngressman Tom Davis -- — about to retire. Now three candidates are in the midst of a spirited race to replace him, jostling over everything from public transportation to the war in Iraq. Join Kojo as the candidates debate key local and national issues. (30 min.) THE DISTRICT'S HEALTH CHECKUP : Washington D.C. has a relatively robust public health safety net. But despite a budget of almost $2 billion a year, the city's Department of Health confronts high rates of heart disease, obesity, asthma and HIV/AIDS. Kojo talks with D.C.'s top public health official about the challenges of promoting a healthier city. (21 min.)