It’s been gone since the 16th and 17th Amendments were ratified. Or, if you don’t think that change was radical enough, since Wikard v. Filburn was wrongly decided.
The only question now is how long before it’s too late to revive the Founding Fathers’ America without a violent revolution — and the answer will become clearer after the next two election cycles. (Not that the revival can be done in a few election cycles, just if they go the right way it will still be feasible, if they go the wrong way, it will soon be time to reach for the cartridge box because soap, ballot and jury will have failed.)
It can’t be revived without massive disobedience: state nullification is the only alternative to violence.