Republicans will filibuster the rule change :)
The thing is..while some Republican is standing up filibustering, Reid can just circulate the rules change amongst the senators...they can vote on the rules change and boom No more filibustering. There is no constitutional rule as to how each Branch has to conduct its business...they can put a law forward and draw black and white marbles; a majority of white marbles drawn and the law passes; if that is how they wanted to do it. Now there are Constitutional laws about over turning vetos, passing laws with such majorities as to be shielded from constitutional scrutiny, quorum numbers necessary to conduct business and the like...ect but as to how they conduct their seessions, the Constitution doesn’t have a say!