Americans with real jobs don't get to simply call it a day and punch out work undone when the clock strikes time. They would be horrified if doctors simply walked off in the middle of surgery because it was the end of the day, likewise with most important jobs.
Being a senator is not like being a fry cook where you could just go home, they are not construction workers that need daylight or anything of the sort. If they don't want to close the debate on a bill and vote on it, there damned well better be debate, even if they have to stand there and read the phonebook.
Let them try to get reelected when their opponent shows ads with them wasting time reading from the phonebook or spouting gobbledygook!