In the three decades before 1980, there were at least a half-dozen occasions when Congress failed to pass a spending bill on time. In each case, the routine functions of government just kept going, more or less on autopilot. Civiletti put a stop to that with a legal opinion that argued that if Congress doesn't say yes to spending on time, it means no.

"At the time, it was seen as a radical break with the easygoing tradition that a little gap was a little gap," Tiefer says. "What's the point of stopping the operation and putting the public to all kinds of inconvenience and difficulties? We should just do the reasonable thing. Attorney General Civiletti was saying, 'You can't do the reasonable thing. You must do what the statute says and shut down.' "

Civiletti actually wrote two opinions. The first addressed a funding gap for a single agency, the Federal Trade Commission. Less than a year later, Civiletti was confronted with a much bigger question when Congress failed to pass spending bills covering most of the federal government. In general, he stuck by his new shutdown rule, although this time he left a little more wiggle room.

"It was very obvious that when the noose was around his own neck, when it wasn't just the little Federal Trade Commission but his own president's whole administration, then he fingered the noose and cut himself a little more slack," Tiefer said.

This second Civiletti opinion carved out exceptions for some government activities including those protecting life and property. In the past week, countless federal workers have spent time trying to figure out whether they fall into one of those exempted categories.

Boston University law professor Alan Feld thinks Civiletti's second opinion leaves the president too much leeway to ignore Congress' purse string power and keep parts of the government operating. But Feld admits it may be in no one's political interest to raise the stakes of these budget showdowns even higher.

"People are just as happy to say, 'Let's have a symbolic shutdown of the government where you can't go to the national parks and you might get a delay in your tax refund, but the Army is going to keep going in Afghanistan,' " Feld says. "Maybe that's a balance that Congress has implicitly approved at this point."

The threat of a shutdown doesn't seem to weigh too heavily on the author of those pivotal opinions. Civiletti couldn't be reached for comment this week. He was on vacation.