And, as stated in clause 2, they can also choose to operate with other than a simple majority.
The Founding Fathers were not enamored of "simple majorities", which is why so many actions laid out in the Constitution require "supermajorities".
No such thing is implied by clause 2. Clearly the majority can set the rules and change the rules, so a majority vote is what’s required by the Constitution, except in those cases specified where a supermajority is required.
Only the GOP is dumb enough to abide by a “shoot yourself in the foot” rule like the current filibuster rule. If Reid hadn’t gotten Obamacare passed via reconciliation, he’d have dumped the filibuster rule. He proved that when he dumped it later for appointments, but only for appointments that mattered at the time.
McConnell was smart enough to dump it for Supreme Court appointments, so there’s absolutely no reason he can’t and shouldn’t dump it for legislation.
As for the GOP not getting rid of Obamacare with a majority, that was a crap piece of legislation they were voting on at the time, and it was only crap because they were trying to abide by the reconciliation procedure. Just dump the filibuster, write a good bill, or a series of good bills, and pass them with a majority vote. This isn’t rocket science. A 7th grade civics class could figure it out.
And if anyone disagrees, please tell me what the justification for maintaining the filibuster is. Certainly the Democrats will cancel it as soon as it’s to their advantage.
And the Founders could have required a "super majority" and they didn't. So they obviously were not too worried about the Senate doing the will of the people.
The U.S. Senators were not seated by a majority or super majority when the Constitution was enacted either.