'Default is nothing more than a failure to pay the interest and principal due on a debt in a timely manner. According to figures in a Power Line post, right now the government is spending about $17 billion every business day. It takes in about $14 billion in revenues. Thus it needs to borrow about $3 billion every business day to make up the difference.
A failure to raise the debt ceiling would prevent the government from borrowing that money. But it would not prevent the government from paying the interest on the debt, which amounts to only about 8 percent of revenues. Nor would it prevent the government from rolling over existing debt, which it does routinely.