When Ben tells Laura that he and Dr. Katz "worked out some platforms," he probably meant to say that they "worked out some planks." A candidates platform is the entirety of what he is forwarding; whereas, planks are the individual points that make up the platform.
Dr. Katz: You really shouldn't use a knife to get toast out of the toaster; that's very dangerous.
Ben: No, I'm not trying to get the toast out; I'm trying to get the fork out.
Dr. Katz: Even the greatest politicians of our time lied. Even Lincoln, what was his nickname?
Ben: Honest Abe.
Dr. Katz: Well maybe that's not a good example.
Ben: "Dad, are you now or have you ever been a member of the communist party?" During the 1950's, Senator Joseph McCarthy conducted what is now known as a witch hunt. He attempted to root out communists from the American government and Hollywood. He asked those testifying: "Are you now or have you ever been a member of the communist party?"