...that Nancy Cartwright originally auditioned for the role of Lisa, but soon thought that her voice would be better suited for Bart, so Matt Groening let her try out for the part and gave her the job on the spot?
...that when it came time to give Grampa Simpson a first name, the writers named him Abraham which by coincidence was the name of Matt Groening's grandfather?
I think the one thing the writers across the board at The Simpsons share, whether they're left or right, is Matt's essential suspicion of authority figures. I think that's what suffuses the show, rather than a political agenda per se. They're on the side of the family, and against all the authority figures and institutions that beset this family.