fortunate son question

[mus]

Hey everybody,

I have a question about the lyrics of Fortunate Son. I'm making a paper about the draft during the Vietnam War and I'm using this song.
What does Fogerty mean with the following lines:

Some folks are born silver spoon in hand
Lord, don't they help themselves, oh
But when the taxman come to the door
Lord, the house look a like a rummage sale, yes

The song is about the men who were lucky enough to have rich parents and the right connections, so they didn't have to go to Vietnam. But what do the taxman and the rummage sale have to do with it?
I hope someone can clear this up for me.

greetings
Eric