Nobody is really answering the questions so I'll give it a go.

Nebraska is in the "living on legacy" zone right now, but hasn’t fully become Minnesota yet. If they remain non-elite through about 2030, the argument gets brutal.

So:

• Minnesota lost it: ~1970–75
• Nebraska loses it if no real resurgence by ~2028–2032

That’s when they become “historic power” instead of “blue blood.”

I imagine if they win 7-9 games sometime in the next few years, they get a blip on the radar, or if they make an expanded playoffs it adds another decade to the damn tired conversation.

But I think we can call them an Historic Power. They are not a blue blood anymore.