Senate Democrats are considering having votes in the middle of the night in order to finish both a Defense Department spending bill and a health care reform measure before Christmas.Sources said Senate rules allow Democrats to hold a filibuster-breaking vote on the Defense measure as early as 1 a.m. Friday if Republicans do not agree to expedite the vote. Under that scenario, the Senate could vote on final passage of the spending bill as early as 7 a.m. Saturday.One complicating factor to holding late-night or early morning votes is the advanced age and poor health of some Democratic Senators, such as the 92-year-old Robert Byrd (W.Va.), sources acknowledged. However, sources said Democrats might feel forced to employ the tactic if GOP leaders continue using time-consuming procedural tools to slow down action on both measures.Either way, Democrats do not expect to have their first vote to break the GOP-led filibuster of the health bill until Monday. But in an attempt to hasten passage of that measure, they may again resort to early morning votes next week.Democrats are likely to file three motions to end the Republican filibuster of the health care measure after final passage of the Defense bill on Saturday, but the rules would prevent them from voting on the first motion to end debate, or invoke cloture, until Monday.In order to pass the health care package, Democrats believe they will have to file cloture on a final, massive package of Democratic amendments, a substitute amendment to the bill, and on the bill itself. Sixty votes are needed to beat back all three filibusters, and Senate Majority Leader Harry Reid (D-Nev.) will likely need all 60 members of the Senate Democratic Conference to prevail. Several Members have yet to commit to voting to end the filibusters until they see an official cost estimate from the Congressional Budget Office, which could be unveiled today.If the majority succeeds in getting enough votes on the first cloture vote on the manager’s package of amendments, they will have to wait 30 hours — essentially until Tuesday — before formally adopting it. They would then likely proceed to a cloture vote on the substitute amendment and wait until Wednesday before adopting that proposal. Finally, a cloture vote on the bill itself would occur Wednesday with a final vote perhaps Thursday, Christmas Eve. Republicans have threatened to disrupt that timeline by forcing a full reading of what is likely to be a nearly 2,500-page bill or using other procedural tools at their disposal. If that happens, Democrats have indicated they might have to push some votes to the week between Christmas and New Year’s Eve.