Drive-by Truckers

I came across a show by these guys recently. They're probably Beatles fans, so that makes them my friends. At least they're John Lennon fans, as they did a cover of Give Me Some Truth in the same show as this next song. Here are the lyrics:

"Once They Banned Imagine"

We had our heart strings dangling ripe for the yanking
And lot of reasons grabby was good
Poor huddled masses singing boots up their asses
Giving grabby what he needed to pull
All the way back to where ghosts from the past were still
Fighting their wars from the grave
Complete with record burning and threatening and spurning
The crime of getting blood on the page
Since the big one ended we'd been mostly pretending
We'd have had the same gumption and grit
As the greatest among us when harm came upon us
We wouldn't hesitate to defend
But with or against something's been out to get us
And it looked like something finally did
No nobler cause in our lifetime for setting our sails to the wind

But once they banned Imagine it became the same old war its always been
Once they banned Imagine it became the war it was when we were kids

Are you now or have you ever been in cahoots with the notion that people can change
When history happens again if you do or you did you'll be blamed
From baseless inquiry
To no knocking entry
Becoming the law of the land
To half cocked excuses for bullet abuse regarding anything browner than tan

Cause once they banned Imagine it became the same old war its always been
Once they banned Imagine it became the war it was when we were kids

I can't quite figure out what they're trying to say. I get most of the references, but what do they mean by "the war it was when we were kids" ?

Any thoughts on the song itself?