Season 7 - The Day the Violence Died
Schoolhouse Rock is a series of shorts illustrating various songs that teach multiplication tables, science, grammar, American history, and economics that were broadcast on the ABC Network.

Krusty: Well, Itchy & Scratchy are gone, but here's a cartoon that tries to make learning fun! [tries to laugh, then moans]

Sorry about this kids, but stay tuned; we've got some real good toy commercials coming right up, I swear.

Big Fat Guy: Good news, Amendment! They ratified 'ya.
You're in the U.S. Constitution!
Amendment: Oh yeah!!!
Congressman: He signed you, Bill! Now you're a law!
Bill: Oh yes!!!
Lisa: So it's true: some cartoons do encourage violence.    
I'm an amendment to be
Yes, an amendment to be
And I'm hoping that they'll ratify me
There's a lot of flag burners
Who have got too much freedom
I wanna make it legal
For policemen To beat 'em
'Cause there's limits to our liberties
'Least I hope and pray that there are
'Cause those liberal freaks go too far.
  I'm just a bill
Yes, I'm only a bill
And if they vote for me on Capitol Hill
Well, then I'm off to the White House
Where I'll wait in a line
With a lot of other bills
For the president to sign
And if he signs me, then I'll be a law.
How I hope and pray that he will,
But today I am still just a bill.
Both lyrics are voiced by Jack Sheldon.
Lyrics from SNPP.COM, plot from Wikipedia and IMDB.COM