"The Republic" is an idea and an idea is dead when no one believes in it any more, remembers what it was or knows/cares what it is supposed to be.
The progressives have been in charge of both parties and most of GuvCo since Bush the elder took over in 1989.
How many generations have been born since and all they know about our Republic is whatever it has become?
How many generations remain who do remember what we used to be and who also had the benefit of a slightly better public education that included American history and civics?
Those who want to fundamentally transform US simply have to outlive us. Once we're gone, that's it. We take it with us.
The melting pot is broken and the schools have become indoctrination centers. No one is filling the well with new to take our place.
Well, some millions of us are teaching our own children.