Weigel

Remember, True Believers: Tonight's debate is supposed to be narrowly tailored in six categories, each of them 15 minutes long. They are:

* America’s role in the world
* Our longest war – Afghanistan and Pakistan
* Red Lines – Israel and Iran
* The Changing Middle East and the New Face of Terrorism – I
* The Changing Middle East and the New Face of Terrorism – II
* The Rise of China and Tomorrow’s World...

Okay, that's actually five categories. But how can the candidates ignore them?

1) They don't need a pretext. In the final 2008 debate, John McCain first mentioned "Joe the Plumber" in response to a question about whether his economic recovery plan would work, and mentioned him again when asked this question: "Given the current economic situation, would either of you now favor controlling health care costs over expanding health care coverage?"

2) If they want pretexts, try this: "Admiral Mullen has said that the greatest threat to our national security is the national debt." That quote gives Romney a magic ticket to take any round back to economics, and back to the debt, where -- though his math is basically 5th-dimensional -- he doesn't have to answer for a $16 trillion overall national debt.