(born May 1, 1964) is an American political strategist and diplomat, serving as United States Ambassador to Switzerland and Liechtenstein since November 21, 2017.Prior to assuming his current role, he was the president of McMullen Public Affairs, an advertising and corporate public affairs company.McMullen was involved with Trump's successful 2016 presidential campaign, acting as chairman of the candidate's South Carolina Republican primary efforts, helping to plan the 2016 Republican National Convention, and serving as a member of Trump's transition team and as vice chair of the Trump inaugural committee.