His father, Gordon Gray, was a lawyer who served as U.S. National Security Advisor under President Dwight D. Eisenhower.

During this time, Gray became one of the main architects of the 1990 Clean Air Act Amendments that suggested market solutions for environmental problems.

Gray returned to Wilmer Cutler & Pickering in 1993, where his practice focused on a range of regulatory matters with an emphasis on environmental issues, including those relating to biotechnology, trade, clean air, and the management of risk.

[9][10] In January 2006, President George W. Bush gave him a recess appointment as United States Ambassador to the European Union.

When Gray emerged as Bush's preferred candidate for the post of the United States' ambassador to the EU in July 2005,[12] the potential nomination deeply perturbed open source advocates, who viewed his ties to Microsoft with suspicion.

[7] Gray was a member of the board of directors at the Atlantic Council, The European Institute, FreedomWorks, and America Abroad Media.