How would the American cultural psyche change in the aftermath of a nuclear war that occured decades ago?

So in my alternate history project, a nuclear war occured in 1980 after the United States fought in World War 3 for five years which reduced the nation into only occupying these territories:

• Oregon.
• Northern California.
• Parts of South East Washington.
• Idaho.
• Parts of Northern Nevada and Northern Utah.
• Montana.
• Some parts of Colorado, Kansas and Oklahoma.
• Nebraska.
• South Dakota.
• North Dakota.
• And some parts of Iowa and Minnesota.

Despite this they are still the largest Post-Nuclear state in the former United States of America and is sometimes considered to be it's true legitimate successor as it carries the mentle though a heavy weight to bare, the nation still wants to cement itself into continuing the legacy of old America.

Now I want to know what insight I can get from you guys about how American culture would have evolved from that point with a nuclear war occuring in 1980, World War 3 occuring 5 years prior and the fact that it's reduced to only occupying these territories. How would it's culture evolve by then? I'd like to know what insight can you give me.