The U.S. Supreme Court upheld a ruling Monday that allows Maryland to count prison inmates at their last known addresses – rather than their prison addresses – for redistricting purposes, and upholds the map approved by the General Assembly last year. Activists had sued the state, saying that the newly drawn congressional districting map violated the U.S. Constitution. The map was developed by a committee appointed by Gov. Martin O’Malley and based on census data and statewide input. It was also drawn to reflect a 2010 Maryland law that counts prisoners at their last known addresses, which differs from the U.S. Census Bureau’s policy of counting inmates at their prison addresses, used by most states.