What Boxer and company really mean by "fundamental rights" is rights that have been written into the Constitution by activist judges precisely because they weren't fundamental enough to have been included in the original Constitution or its amendments or uniformly passed into law by federal or state legislative bodies. They mean rights whose continued existence depends upon Supreme Court justices affirming erroneous precedent established by their activist predecessors.
This is much more serious than it sounds. In demanding that would-be justices uphold precedent that has no grounding in the Constitution, Boxer and her like-minded colleagues are trying to extract a commitment from them that they will conspire to disenfranchise the people.
Though they're always boasting that most Americans support abortion rights, these senators obviously don't want to take the chance that Roe will be reversed, because state legislatures may decide to outlaw or more strictly regulate abortion. Thus in the name of protecting "fundamental rights," the will of the people and the integrity of the Constitution, they circumvent the will of the people and undermine the Constitution.
In a nutshell, that's what's so sinister and insidious about this "progressive" notion that the Constitution is an evolving document. When judges can make the Constitution say whatever they want it to without regard to the original understanding of those who signed and ratified it, the fixed basis upon which all our rights depend degenerates from concrete to sand. Our constitutional rights are no more secure than the whims of the unaccountable majority of the current Supreme Court.
I just wish that one time one of these sanctimonious senators started lecturing a nominee about a woman's fundamental "right to choose," another senator or the nominee would have the courage to throw back in his face the sanctity of the Constitution. I wish that one time a ranting senator began railing about the potential loss of "fundamental rights" someone would point out that the extraconstitutional method for creating mythical fundamental rights places in jeopardy our entire constitutional scheme of rights and liberties.
Instead of, or at least preceding, the inevitable rash of pseudo-indignant sermons from constitution-disrespecting senators about "fundamental rights," we would be better served by a national dialogue on the fundamental importance of preserving the original understanding of the Constitution.