They just threw America’s credit rating off Boston harbor.

The privately owned profit-making agency that fueled the economic crisis of 2008 by ranking Wall Street collections of junk-mortgages AAA has downgraded obligations of the United States to AA+, after a half-day delay to consider a Treasury Department notification of a $2 trillion error in their math.

In the world we live in, this move will shake confidence not in Standard & Poors but the U.S.

Even worse, the rationale for “the downgrade reflects our opinion that the fiscal consolidation plan that Congress and the administration recently agreed to falls short of what, in our view, would be necessary to stabilize the government’s medium-term debt dynamics,” citing “political gridlock” in government policy-making.

Translation: They are dampening their pants over Tea Party terrorism in the debt-ceiling deal and covering their posteriors over the prospect of more of the same.

As the White House and GOP prepare to point fingers at each other in a blameathon, it might be noted that one of S & P’s recommendations for a remedy is that Washington try to reduce the deficit by $4 trillion over 10 years and that anything less would be insufficient.

MORE.