Answer:
There does not seem to be any true consensus about what constitutes a fundamental right. The jurisprudence of the United States Supreme Court has generally held that a fundamental right is one which is "so deeply rooted in the collective tradition and conscience of our people" that it is ranked fundamental. Of course, this is circular logic, but it highlights the difficulty associated with defining such a subjective philosophical term.
However, in the past the Court has found several things to be "fundamental." Family autonomy, procreation, sex, sexual orientation, reproductive autonomy, ability to purchase and use contraceptives, an expecting mother's choice to terminate a pregnancy, medical care, refusal of medical care, interstate travel, voting, access to courts, speech, religion, privacy, property ownership, and a parent's interest in the care and companionship of their child have been named as fundamental rights. Right to education and welfare benefits have been denied "fundamental" status by the Court.