President Obama is facing a deepening dilemma about whether to abandon cuts to Social Security in his next fiscal blueprint, which is due out in March. Obama touched the third rail of American politics last year when he proposed a new formula for Social Security and other entitlements that would result in benefits being cut over time. Now congressional Democrats and unions are ramping up their pressure on Obama to drop the proposal, which many fear could become an albatross for the party in the midterm elections. “We want the president to make very clear that he is going to...