The United States has officially lost its perfect credit rating. On Friday, Moody’s, for the first time in its history, downgraded U.S. government bonds from the gold star rating of “AAA” to “AA1,” the silver medal equivalent. This wasn’t a total surprise. S&P and Fitch had already lowered the U.S. rating, so this was Moody’s catching up to the crowd. But make no mistake: Moody’s didn’t just pick a random Friday in May to make this move. Moody’s wanted to send a message to Republicans in Congress: Rethink the tax bill. Or, better yet, don’t do it. …The Republicans’ bill would add at least $3.3 trillion to the debt over the next decade. …Moody’s cited concern over how big the U.S. debt already is (more than $36 trillion) and how Congress has taken almost no action to stop the annual deficits that keep adding to that tab. [to access the full story a Washington Post subscription is required]