“Senate rules forbade members from speaking more than twice per day on a given piece of legislation, but a senator was free to offer as many amendments to the bill as he wished and could then speak twice on each amendment. ….
[Preparing to filibuster FDR's plan to 'pack' the Supreme Court, Senator Edward Burke of Nebraska] procured a stack of official amendment blanks and charged a group of young American Bar Association lawyers with the task of filling them in. After a day and half the lawyers had drafted no more than 15 amendments, each of which substantially altered the court bill.
“Exasperated, the men paid a visit to Senator [Josiah] Bailey, who laughed out loud at their paltry output. Reaching for a copy of the bill, he told one of the lawyers to take dictation. Bailey pointed to the provision that set a limit of 15 judges, and instructed the lawyers to replace ’15’ with ’14’. Then ’13’. Then ’12’. And so on through the various sections of the bill. Having received this lesson in legislative hair-splitting, the lawyers produced 125 neatly amendments by the next morning — enough to permit 250 speeches.”
— From “Supreme Power: Franklin D. Roosevelt vs. the Supreme Court” by Jeff Shesol (2010)