Maybe this is why the nostalgia/agitprop combo platter offered by the “West Wing” get-out-the-vote reunion special goes down so easily for so many, on all sides of the political spectrum. With American political discourse where it is today, who doesn’t take some solace in Sorkin’s earnest yet quippy dreams of reason and empathy in national politics? It’s a lovely break from the ongoing American argument. That argument, as we see in “Nationtime,” “City So Real,” “What the Constitution Means to Me” and “The West Wing,” holds no promise (let’s hope) of a season finale, nor of a fixed definition of politics, or liberty, or justice for all. The argument is America, the fractured, beautiful and ever-changing.