So it's happened -- right or wrong: a downgrade of Uncle Sam's credit for the first time in history.
Standard & Poor's announced Monday that it was also downgrading the credit of Fannie Mae and Freddie Mac one notch, to AA+ from AAA, its very highest rating. The two agencies guarantee or own more than half the $5 trillion in home loans in the U.S.
"The downgrades of Fannie Mae and Freddie Mac reflect their direct reliance on the U.S. government," said Standard & Poor's in a statement.
The downgrading of Fannie and Freddie "was inevitable," said Robert Litan, a former Clinton administration budget official who is now vice president for research and policy at the Kauffman Group. "If the U.S. government is downgraded it follows logically they would have to be downgraded too."
What's next, asked Litan?
"The states and locality ratings will be next because of the interest rates benchmarked against U.S. treasuries so there is a linkage between that debt," he said. "In an environment of budget austerity this is not good for states and localities. This will trigger another closer look at state and local finances. Some states that were in in trouble already and some in the bubble."
Lots of people will be wondering what this means for the real economy and the stock market. Here's a quick primer based on ABC News' extensive reporting on the possibility of a downgrade -- five easy to understand effects:
1. The interest rates the government pays to finance the growing national debt will almost certainly rise as a result of the downgrade. That increases the amount of money Uncle Sam has to spend each year on "debt service." General market discussions have turned on an increase in rates that would up the annual tally by about $10 in the short-term and go up to $75 billion in additional costs in the coming years.