First of all America is a Republic not a Democracy, at least not in the pure sense of the word. In a pure Democracy 51% could vote to take the rights of the other 49%. In a Republic we accept majority rule but at the same time the majority must respect the rights of the minority.
However what you are referring to has to do with the Senate rules for fillibuster. That is not the same thing. There is no constitutional provision either for or against the fillibuster. The fillibuster is an idiotic procedure whereby one Senator talks and talks and talks about some arcane subject until everyone else falls asleep. Its a stalling tactic used to prevent real discussion until everyone gives up and moves on to another subject. It should probably be done away with.
So, when democrats get control of the senate again, how do you plan on stopping them from doing whatever they want?