 Lefkowitz is credited as, while serving as General Counsel in the White House's Office of Management and Budget, having been the architect of President George W. Bush's decision to allow federal money to pay for some amount of research on stem cells from human embryos.As envoy for North Korean human rights, Lefkowitz referred to the North Korean government as a "criminal regime," criticized those who provide Pyongyang with assistance, and urged that China respect the rights of North Korean refugees.In two major cases before the Supreme Court of the United States, "Pliva Inc. v. Mensing", (564 U.S. 604 (2011) and "Mutual Pharmaceutical Co. v. Bartlett", 570 U.S. 472 (2013), Lefkowitz succeeded in persuading the Supreme Court that because federal law absolutely demands that generic drugs precisely follow the FDA-approved labels of the related brand-name drug produced by another manufacturer, states may not impose liability on generic manufacturers who do nothing but use the labels federal law requires them to use.