Inside the sleek hillside headquarters of Valley Health Systems, built with a grant from the health care law, two employees played an advertisement they had helped produce to promote the law's insurance coverage for young, working-class West Virginians. The ads ran just over 100 times during the recent six-month enrollment period. But three conservative groups ran 12 times as many, to oppose the law and the local Democratic congressman who voted for it. This is a disparity with consequences. Health professionals, state officials, social workers, insurance agents and others trying to make the law work for uninsured Americans say the partisan divisions and attack ads have depressed participation in some places.