Perhaps I was unclear I don't know of anything that would force an opponent to take the floor either.
What I meant is in order in the past of the rule of unlimited debate in order to filibuster a Senator in opposition would acquire the floor in open debate and refuse to yield as long as he could.
He had to remain on the floor,remain standing and keep speaking.
If he did not do these things then a member in favor could request recognition get it and he would control the floor .
Then he could offer a motion to vote or proceed to the vote. All that then would be required to carry a floor vote is simple majority.
Once you get to the floor in the Senate all that is required to pass anything, is a simple majority vote.
Unless a super majority is required by the Constitution such as to convict or overturn a Presidential veto etc., majority rules.
Unanimous consent or the filibuster until this cloture agreement could be broken by simple majority vote 51 once the floor had been acquired by a Senator in favor of passage.
It was in this agreement that the super majority which was originally 2/3=65 and reduced later By Byrd when they where in the majority to 3/5= 60, came about. Like I said a filibuster was used to delay action while others worked to have voters switch their vote on an item.
Now a group of senators in the past could get together and just decide to filibuster any and everything to just disrupt and delay the Senate but they had to do so physically by continually speaking on the floor.
They couldn't filibuster by simply signing a piece of paper and then heading home or to the nearest party or resort.
The ones who pulled these things not only interrupted their on family and / or social life but everybody else's. This did not make them popular even with their own colleagues.
That's partly true, but not all true. A simple majority does carry as a rule, except, as you pointed out, for treaties, conviction in the case of impeachment, and one or two other things.
But the hurdle is getting to that darn vote. That step (scheduling the vote on the underlying measure, even if it's for "right now") takes unanimous consent. Cloture is a substitute for unanimous consent to take the vote. The only thing required in order to delay a vote is to withhold consent to take the vote.