Booker's speech so far has covered several topics, including cutbacks to Social Security, research funding, immigration, national security, and more, taking often-lengthy questions and statements from Democrat senators throughout the night without yielding the floor.
Such questions and comments are allowed under Senate rules, but Booker must remain standing to hold the floor. During the night, he took questions from Sens. Andy Kim, D-N.Y., and Chris Murphy, D-Conn., and early Tuesday took comments and statements from Sen. Kirsten Gillibrand, D-N.Y.
In 2016, Murphy took the Senate floor for a 15-hour filibuster to demand gun-control legislation after the Pulse nightclub shooting in Orlando.