We’ve long argued that the government should not endorse any company’s opinions about credit risk, which at the end of the day is all a credit rating is—an opinion. And for that reason the government will not have an easy time making a fraud case. …

So why wasn’t a federal case made in 2008 or 2009 or 2010 or 2011 or 2012? In the United States it has always been difficult to prosecute publishers of financial opinions for securities fraud. Yes, the SEC has sometimes successfully prosecuted the proprietors of sham newsletters that touted stocks with bogus claims while secretly accepting payments from the companies being hyped. …

There are other disturbing questions related to the timing and the target of this federal civil prosecution. S&P’s attorney Floyd Abrams tells us that “things seemed to rev up in terms of the intensity” of the federal investigation after S&P’s historic downgrade of United States credit following Washington’s debt-limit fight in 2011. …

Speaking of the debt-limit fight, that’s also coincidentally when White House Chief of Staff Jack Lew was aggressively promoting the President’s campaign to prevent entitlement reform. Mr. Lew had worked in the heart of Citigroup’s C +1.68% subprime investment factory, and the President has not only been willing to forgive and forget. He’s even nominated Mr. Lew to become Secretary of the Treasury. But the company that put a shot across the Beltway bow over deficit spending is now the only target of a credit-ratings prosecution.