It should be the old fillibuster: on the floor speaking.
That worked and there was no good reason to change it.
Filibustering is just the way the minority party uses to try to slow and stop the ruling party’s progress.
“The cloture rule was adopted at a time when deliberations in the Senate had ground to a halt, frustrating President Wilson during a time of war.
At the end of the session in 1917, lawmakers filibustered for 23 days against Wilson’s proposal to arm merchant ships, according to the Senate Historian’s office. The delay tactic also hampered efforts to pass other important legislation.”
I guess if filibuster could be used to stall Executive actions in time of war it may not be such a great idea.