A professor of mine — a leading star in anthropology with a towering, critical mind — pointed out to us students on Thursday that we should be asking what kind of change Barack Obama will really bring.

Make no mistake: this prof was happy about Obama, and couldn’t hide it. I don’t think he had any intention of dampening the classroom’s euphoria, either (there are like two McCain supporters at SIPA). But it’s his job to think about these things, so I think we’d do well to listen.

What he pointed out was that there’s lots we don’t know about the Obama presidency. Will he deepen the occupation of Afghanistan? Isn’t the United States’ superpower status so predicated on a powerful military that we will need ever more expeditions to stay relevant? Hasn’t Obama worryingly surrounded himself with interventionists like Samantha Power? (In my prof’s view — or what I understand of it from his class — Power’s take on what the U.S. should have done in Rwanda was wrong and didn’t account for the country’s history.) And what of a resurgence of patriotism — even jingoism — that could mean a blank check on dubious policies? (We’ve seen that one before!)

In short, my prof was saying that the president can only be as big as the presidency. I think he’s is right.  And there are far more constraints on Barack Obama than there were on W, for two reasons. One, Obama truly was elected by a grassroots campaign, and so must in some ways be held to the whims of his grassroots. Two, the changes he wants to make — and that progressives hope he makes — are more revolutionary than the kind of changes Bush began 2000.

I had already been thinking about the limits and challenges of an Obama presidency because of some observations I made while canvassing in Ohio. For one thing, there are those in America that hate what Obama stands for. Like it or not, they vote, and we must bring them into the dialogue if we ever want lasting change in our country. Without that, the Christian right will just end up hating Obama as much as progressives hate Bush.

Another thing is that there is certainly not unity among Obama’s supporters on all issues. In the post-euphoria of the election, we shouldn’t shy away from looking at our fellow Obama supporters and asking them what they think about really difficult issues: abortion, gay marriage, immigration, Israel and Palestine. And while we all agree that our current foreign policy is terrible, there is wide disagreement about what the correct one looks like. One Obama supporter told me he thinks Iraqis should pay us back for the cost of the invasion. I totally disagree. The fact that we were able to agree enough on the campaign to drive around in the middle of the night before E-Day planting Obama signs is testament to the power of Obama’s message. But the discussion is not resolved.

We don’t need immediate consensus, but we must have dialogue. We can all crawl back to the rocks we live under — liberal, conservative, coastal or heartland — and wait for Obama to answer all these questions for us. Or we can keep up the amazing hope and dialogue this campaign has started, so we are never surprised by the views our fellow voters come up with, and so that when we hit impasses, we know how to solve them in ways beside shouting at each other, or worse.

Here’s an issue we can start with: Obama’s reported plan to come up with an alternative justice system to replace Guantanamo. Is this what we want? The ACLU has criticized it. On the other hand, it’s a way to get the travesty of Guantanamo off our hands with the quickest consensus possible. I don’t know enough yet to give a strong opinion (though when the ACLU speaks, we should listen). All I can say is: Stay abreast, stay engaged, don’t get passive!

Finally, a shout out to my fellow canvasser and blogger Seth Wessler, who is doing his part to promote this dialogue with his excellent blog posts via Racewire, which is associated with the magazine Colorlines. I love these anecdotes from Ohio (Seth stayed in the same house I did in Lancaster).