Yep, this is exactly how they are able to achieve it and will probably continue to. For a legal document, The Constitution is pretty weak and ambiguous on what authority the government has, the means of exercising power, and defined limits or procedure for operating. This is an inherent problem with any government, as it has the monopoly on force and incentives to expand its domain for any number of reasons.

I think the first big shift happened with Oliver Wendell Holmes and the move away from originalist interpretation. Arguably this was bound to happened, and will continue to expand further out. The Constitution is honestly just given a nod and has little bearing on law at this point.

That's a farce. The 4th amendment is still being violated even if we accepted that.