Senate Democrats on Tuesday morning cleared a second hurdle on their way to passing landmark health care reform legislation by Christmas, voting to kill a Republican filibuster of a key amendment related to the $871 billion package.The outcome was not in doubt. Senate Majority Leader Harry Reid (D-Nev.) secured the necessary support of his 60-strong Democratic Conference over the weekend and successfully tested that coalition during a 1 a.m. Monday procedural vote to move forward on the bill. Still, Tuesday’s 7:20 a.m. vote further solidified Reid’s coalition behind the health care bill.The package faces a one more procedural hurdle before moving to final passage, which is expected Christmas Eve night.Tuesday’s vote ended debate on the substitute amendment to the bill; Monday’s vote beat back a GOP filibuster of the manager’s amendment, which contains the compromise language that Reid negotiated to win over centrist holdouts like Sen. Ben Nelson (D-Neb.).The third and final cloture vote on health care, this one on the underlying legislation itself, is set to occur Wednesday afternoon.Even though Democratic support for the bill seems solidly intact, the Republicans on Monday said they would continue to try to draw out consideration of the measure.