It’s one of the most pressing issues facing the country, and a question that’s never been tackled by federal courts, according to Bradbury. Under the circumstances, OLC would have to go further than it has in the past, and issue a formal opinion on the Constitutionality of the debt limit statute itself.

“This would absolutely require a significant written opinion by the OLC before the President would rely on it,” Bradbury said. If it came to crunch time, the office could have such an opinion ready in less than a day. “When the White House calls, OLC gets to work and gets the opinion to the White House.”

These procedural issues, though weighty in and of themselves, would be merely the opening salvos of a multi-round fight with the GOP if the administration determined it had the Constitutional authority to ignore the debt limit. The courts would get the final say on the legal question, and the political backlash would be swift. In 1995, some Republicans called for resignations at the Treasury Department over the comparatively minor steps Secretary Robert Rubin took to avoid default. Gingrich even convened a task force to explore legal action against the Clinton administration. If Obama ignored the debt ceiling statute altogether, calls for impeachment would surely follow.