Less than two months after 9/11, South Park gave us an episode titled "Osama bin Laden Has Farty Pants." Now, the toon takes on the U.S.-Iraqi war. To help plot tonight's 100th episode — airing 10 pm/ET on Comedy Central — co-creators Trey Parker and Matt Stone called in heavy reinforcements. Namely, their idol-turned-fan Norman Lear.

The 80-year-old's passion for inspiring youth to civic activism fueled what Parker modestly refers to as a "very somewhat special episode" of the series. Tune in, and you'll find everyone's favorite fourth graders joining in anti-war protests because they believe in, well, cutting class. Their pro-war teacher Mr. Garrison strikes back by assigning them book reports on the nation's founding fathers. And Cartman, rather than (gulp) reading, flashes back to 1776, just in time to wreak havoc on the signing of a certain historical document.

This storyline is naturally near and dear to Lear. The All in the Family producer paid $8 million for one of 25 original copies of the Declaration of Independence, which he currently has touring America for public view. "I think of myself as a bleeding heart conservative," he says. "Conservative because you dare not fool with my First Amendment, my Bill of Rights, my Constitution."

While Lear and the South Park scribes don't agree on everything — "They think in my heart of hearts I'm a Republican [like them]," he laughs, "and I'm convinced in their heart of hearts they're progressive!" — they do share a strong belief in freedom of speech. Parker and Stone have taken full advantage of that by dissing Lear's Family on their show (sorry, Sally Struthers) and in conversation (this means you, Meathead).

"It's funny because we hate Rob Reiner way more than we hate Sally Struthers," Parker says. "He's the anti-Christ, really, when it comes to political things. So at our pre-season writers' retreat, we're like, 'So Norman, how do you feel about Rob Reiner?' He's like, 'Oh, he's like a second son to me.' And we're like, 'Ah, he's a piece of s---.' That's just how cool Norman is. He's just like, 'Whatever kids, you don't f---in' know anything.' And he's right."