Everyone's always saying they're so worried about America's big button, the one that controls all the nuclear power. I'm not worried about that... I'm worried about the idiot on the end of it.
Worry About the Idiot
Explanation
Explain Bear
Okay, you dummy, let me break it down. You see, the joke is about how people are worried about nuclear weapons, but the real problem is who's in charge. It's not the button that's the issue; it's the person who has control of it, and that person might be an idiot! Like you might be an idiot.