MICHAEL BARONE: Blame James Madison For The Government Shutdown.

The current divisions result from what I call volitional migration in my just-published book, “Shaping Our Nation: How Surges of Migration Have Transformed America and Its Politics.” Americans have been moving to places they consider culturally congenial.

Democratic voters—blacks, Hispanics, gentry liberals—are heavily clustered in certain central cities. They give Democrats an advantage in the Electoral College.

Republican voters are more evenly spread around beyond these Democratic bastions. That gives Republicans an advantage in the House of Representatives.

So both sides have a legitimate mandate — but not an unlimited one.

Republicans are furious that their members can’t defund or delay Obamacare. They want to see politicians stand up yelling, “No!” Theater has a function in politics.

But in fact, they’ve had a partial victory this year, a win that didn’t seem likely last December. By accepting the sequester despite its defense cuts, Republicans have actually dialed down domestic discretionary spending.

Democrats’ position now is essentially the sequester. They’re swallowing something they hate. No wonder Obama seems sullen.

So both sides will have frustratingly partial victories and not get everything they want. That’s how James Madison’s system is supposed to work in a closely divided country.

Indeed.