Changing the filibuster (say, dropping it to 51 votes or killing it entirely) is the Senate voting to update its own internal playbook.
They can do that with a simple majority vote because the Constitution says the Senate gets to "determine the Rules of its Proceedings" (Article I, Section 5).
No Constitutional amendment is needed
The Constitution says you must have a Senate. It doesn't say the Senate must let one guy stall everything with endless talking. That rule is just something the Senate invented and can un-invent whenever 51 of them feel like it.
They can do that with a simple majority vote because the Constitution says the Senate gets to "determine the Rules of its Proceedings" (Article I, Section 5).
No Constitutional amendment is needed
The Constitution says you must have a Senate. It doesn't say the Senate must let one guy stall everything with endless talking. That rule is just something the Senate invented and can un-invent whenever 51 of them feel like it.
