With respect, I disagree. There is an important distinction between the Court's right to interpret what the constitution sets as rights, versus the Court having an independent authority to define rights on their own. If the constitution doesn't set something as a right, the Court has no authority to set one. Using a baseball analogy, the Court is an umpire, not a player. The Court can only say whether a player hit a home run. They can't add a run to the scoreboard on their own.

The way this works is that the authority of the law comes from the consent of the governed. But that consent also includes what those agreed-upon laws logically imply. If the law specifically says no to something, it also says no to whatever that something implies. To be clear, the Court never says that the Constitution specifically opposes abortion. What it says is that the amendments imply a right to privacy (which is true) and that that right of privacy implies abortion (with which we strongly disagree). We agree with the first implication, but not the second. And that's a matter of logic, not just opinion.

As for originalism, we see it this way. The Constitution is essentially the social contract. It's how we have mutually agreed to live together. Every law and statute under that constitution is like a proposed modification to the original contract. All of these come by mutual agreement, and the legislature is where we haggle those agreements. Like any other contract, though, you can't make modifications to the contract unilaterally. Any change in the contract has to be agreed to by all parties involved, otherwise the change has no force of law. And like any other contract, the meaning of the clause is whatever the parties agreed to, and only as they agreed to it.

The fallacy of the "Living Constitution" is that it argues that a privileged few can make changes to the terms of the contract, or reinterpret the terms, without needing the agreement of everyone else. No. It's a contract. You can't change a contract unless all of the parties consent.

Sorry for the length - I get passionate about this topic.