An election schedule to replace disgraced former Rep. Randy "Duke" Cunningham caused at least one candidate to drop out of the 50th District race yesterday and could force those seeking the seat to run in as many as up to three races in two months. Candidates will vie in a special primary election April 11 to serve the last six months of Cunningham's term. Then, on June 6, there could possibly be a runoff, the same day as a separate primary for the full two-year term. "We're sort of in uncharted waters," said Joe Justin, a consultant for state Sen....