Rush Limbaugh actually lent his own voice for Family Guy's episode about the Republican party. He and John McCain solves a Scooby Doo-style mystery, George W. Bush acts like a child, and a GOP-themed musical number, inside.
When Brian befriends Rush after reading his book and then being saved from a gang of bullies, the accepts the invitation to go inside the Republican National Headquarters. How many familiar Republican faces can you find?
Later on, Brian and Rush make a statement about their political views in a musical number titled "Republicantown."