Mayor - in this case the bill was being debated in a special session that ran until midnight. If had to be voted on by midnight in order to be a valid vote.
From what I've read it seems likely a second, longer special session will be called and the bill reconsidered. It's unlikely the democrats will be able to filibuster a longer session. But it also seems likely the law is unconstitutional anyway...
Filibusters are very much the sort of thing where if you agree with them they're brilliant and if you don't they're a bit of a blot on democracy, though the stamina required for them is impressive in its own right.
In the US most legislatures have an odd mix of populist maxi-democratic levers, like recalls direct vote propositions, and brakes on democracy, like the filibuster and the constitution. When the US was set up the people were not overly trusting of government power, and the brakes were an attempt to protect the people from a dictatorship of the majority.