The two biggest credt rating agencies on Wall Street are now warning that the U.S. could lose its top bond rating:

Two leading credit rating agencies on Thursday cautioned the U.S. on its credit rating, expressing concern over a deteriorating fiscal situation that they say needs correction.Moody's Investors Service said in a report Thursday that the U.S. will need to reverse an upward trajectory in the debt ratios to support its triple-A rating."We have become increasingly clear about the fact that if there are not offsetting measures to reverse the deterioration in negative fundamentals in the U.S., the likelihood of a negative outlook over the next two years will increase," said Sarah Carlson, senior analyst at Moody's. Standard & Poor's Corp. on Thursday also didn't rule out changing the outlook for its U.S. sovereign-debt rating because of the recent deterioration of the country's fiscal situation. The U.S. currently has a triple-A rating with a stable outlook at both agencies."The view of markets is that the U.S. will continue to benefit from the exorbitant privilege linked to the U.S. dollar" to fund its deficits, Carol Sirou, head of S&P France, said at a Paris conference Thursday. "But that may change. We can't rule out changing the outlook" on the U.S. sovereign debt rating in the future, she warned. She added the jobless nature of the U.S. recovery was one of the biggest threats to the U.S. economy. "No triple-A rating is forever," she said.

No triple-A rating is forever? Yikes. As Kevin Williamson says, "Note to Washington: If you thought the Tea Party looked like an angry mob, wait until you see what happens when Social Security checks start bouncing."