Because they have rubbers on their end.
Your looking Sharp!
Because they're made out of graphite
Don't worry baby, I'm sterile.
A baby.
They both tell the audience what they are glad to hear. But at the end, the audience laughs at the comic, and the politician laughs at the audience.
They always end in a draw
Because a vasectomy would heal in seconds and he doesn't look like he'd wear a rubber or pull out.