Standard & Poor’s this week deployed legal countermeasures against the federal government by asking a judge to dismiss a civil fraud lawsuit brought against the rating agency, slamming the litigation as an “overreach.” In February, the Justice Department filed a $5.0 billion lawsuit against S&P accusing it of knowingly inflating its ratings on residential MBS and collateralized debt obligations to boost its revenue and market share in the years leading up to the 2008 financial crisis. The filing in California federal court by S&P’s parent company, McGraw-Hill Co., says...