The conventional wisdom is that failing to raise the debt ceiling constitutes a default. If only. Let's take a closer look. All else being equal, we still have the coveted Triple A credit rating. So putting our bills on our credit cards isn't a problem. Sure, the interest payments are a drag on the economy, but as long as we pay our bills eventually, we're still trusted.
As for default? Well, defaults happen all the time for regular folks--it's a simple matter of filing for bankruptcy protection and paying off creditors one by one.
What's under discussion here is voluntarily cutting up our credit cards right when our bills are due. These are bills for existing obligations--continuing the analogy with personal finance, imagine what happens when you refuse to pay a bill, like, say, your electric bill. Typical result? Refusing even to put something on your card--effectively, refusing even to write an IOU to the other party--is hardly default. It's delinquency. Possibly a civil offense. This will get ugly.