Oh, well I heard the opposite. I heard Vinick was originally supposed to win, and they actually intended on continuing the show with him as president, but then the network canceled the show, and they decided it would be more conclusive if Santos won. And I never thought of Vinick as a centrist at all. If anything he seemed very libertarian, which I would consider more right-leaning than someone like McCain. For liberals though McCain and Vinick are both "centrists."
I forget what vouchers convo you're talking about. I remember there was a vouchers conversation in the first or second season between Sam and Leo's daughter where Sam rambled on about the virtues of the public school system.