Why to you suppose they keep voting on these over the weekend?

Maybe they hope people aren't paying attention?
http://thehill.com/homenews/senate/68777-key-senate-health-vote-set-for-saturday-night

Senate health vote set for Saturday night

By Alexander Bolton - 11/19/09 07:08 PM ET

Senate Democrats have cleared the way for a Saturday night vote to begin the healthcare debate, a Democratic aide said.

 
Sen. Tom Coburn (R-Okla.) has agreed to relent on his demand for Senate clerks to read aloud the 2,074-page bill and allow the chamber to take a critical test vote, said the aide. Reading the bill on the Senate floor was estimated to take as many as 30 hours or longer, raising the possibility of the Senate staying in session into next week.
 
The agreement to dispense with time-consuming procedural hurdles means that lawmakers will be able to catch flights back to their home states later in the evening on Saturday or early the next morning. This comes as welcome news for aides and other congressional workers who wrestled with the prospect of the Senate extending its session until Tuesday or Wednesday.
 

The Senate will vote at 8 pm Saturday to cut off debate on a motion to proceed to the healthcare reform bill. If 60 senators support the motion, the chamber would automatically adopt the motion to proceed to the bill and then depart. The Senate would begin amending the bill after the Thanksgiving recess.