It appeared that a compromise brokered Friday night on the volatile issue of abortion had finally secured the votes needed to pass the legislation. As drafted, the measure denied the use of federal subsidies to purchase abortion coverage in policies sold by private insurers in the new insurance exchange, except in cases of incest, rape or when the life of the mother was in danger. But abortion foes won far stronger restrictions that would rule out abortion coverage except in those three categories in any government-sold plan. It would also ban abortion coverage in any private plan purchased by consumers receiving federal subsidies.