President Bush’s popularity ratings — once among the highest of any president in the past 60 years — are eroding across the board, according to a new NBC News-Wall Street Journal poll. Bush is losing ground in several key areas, including foreign policy, the economy and his handling of the war on terrorism. And as the escalation of U.S. forces in the Persian Gulf continues, the poll finds a growing number of Americans oppose military action to remove Iraqi President Saddam Hussein from power. The president’s overall approval rating slipped to 54 percent, down from December’s 62 percent and a...