Eight Senate Democrats are opposing speedy action on President Barack Obama’s bill to combat global warming, complicating prospects for the legislation and creating problems for their party’s leaders. The eight Democrats disapprove of using the annual budget debate to pass Obama’s “cap and trade” bill to fight greenhouse gas emissions, a measure that divides lawmakers, environmentalists and businesses. The lawmakers’ opposition makes it more difficult for Democratic leaders to move the bill without a threat of a Republican filibuster.