Washington (AP) - A year in the making, sweeping health care legislation backed by President Barack Obama hung in the balance Thursday as conservative Democratic Sen. Ben Nelson withheld his vote in pursuit of stricter abortion limits and liberals grew restive on the left.

Any lingering hopes the bill's supporters had of a Republican casting a critical 60th vote vanished when Sen. Olympia Snowe, R-Maine, said after a meeting with Obama that the Democrats' timetable for a pre-Christmas vote was "totally unrealistic."

Nelson, the most conservative Democrat in the Senate, was vague throughout the day about his intentions, eventually telling reporters, "I hope we're getting closer" to agreement...