Question: David Wurmser served as special assistant at the State Department to a diplomat that was appointed  U.S. ambassador to the United Nations by what president?

Context articles: James B. Cunningham
John R. Bolton
Brett H. McGurk
Gene Cretz
Joseph E. Davies
Incumbency advantage for appointed U.S. Senators
Zalmay Khalilzad
Stuart Holliday
John Van Antwerp MacMurray
David Wurmser

James Blair Cunningham (born 1952) is an American diplomat and the former United States Ambassador to Afghanistan.
 Cunningham has served in various diplomat positions since graduating from Syracuse University in 1974.
 Positions that he has previously held include Chief of Staff to NATO Secretary General Manfred Woerner (1989-1990), Deputy Advisor for Political Affairs at the United States Mission to the United Nations (1990-1992), Director of the State Department's Office of European Security and Political Affairs (1993-1995), Deputy Chief of Mission, Embassy of the United States in Rome (1996-2001), Acting United States Ambassador to the United Nations (2001), Consul General of the United States to Hong Kong and Macau (2005-2008) and the United States Ambassador to Israel (2008-2011).
John Robert Bolton (born November 20, 1948) is an American lawyer and diplomat who has served in several Republican administrations.
 Bolton served as the U.S. ambassador to the United Nations from August 2005 until December 2006 as a recess appointee by President George W. Bush.
 He resigned in December 2006, when the recess appointment would have otherwise ended, because he was unlikely to win confirmation from the Senate in which a newly elected Democratic Party majority would be taking control in January 2007.
Brett H. McGurk (born April 20, 1973) is an American lawyer and diplomat who was appointed by President Barack Obama on 23 October 2015 as Special Presidential Envoy for the Global Coalition to Counter ISIL.
 He replaced General John R. Allen to whom he had been a deputy since 16 September 2014.
 He also served as Deputy Assistant Secretary of State for Iraq and Iran, at the U.S. Department of State, and from October 2014 through January 2016 led 14 months of secret negotiations with Iran that led to a prisoner swap and release of four Americans from Evin Prison in Tehran, including the Washington Post journalist, Jason Rezaian.
 This assignment, among others, reinforced McGurk's "reputation as a doer", according to the NY Times.
 He earlier served under President George W. Bush as Special Assistant to the President and Senior Director for Iraq and Afghanistan, and under President Obama as Special Advisor to the U.S. National Security Council and Senior Advisor to the U.S. Ambassador to Iraq.
 An attorney by training, Mr. McGurk served as a law clerk to Chief Justice William H. Rehnquist on the U.S. Supreme Court during the Court's 2001 October Term.
 On January 19, 2017, President-Elect Donald Trump's press secretary Sean Spicer announced that the incoming administration would retain McGurk in his role leading the counter-ISIS campaign.
Gene Allan Cretz (born 1950) is a career diplomat who retired from the Senior Foreign Service in 2015.
 Before retiring, he was the U.S. Ambassador to Ghana.
 Before this, he was the first U.S. Ambassador to Libya since 1972, after being nominated in July 2007 by President Bush.
 His nomination was confirmed by the US Senate on November 21, 2008.
 He was sworn-in as U.S. Ambassador to Libya by Secretary of State Condoleezza Rice on December 17, 2008, at the State Department.
 He arrived in Libya on December 27, 2008.
 Cretz speaks a number of languages, including Arabic, Dari, Urdu, and Chinese.
 President Barack Obama nominated him for the post to Ghana in April 2012.
 He was sworn-in as the U.S. Ambassador to Ghana by Secretary of State Hillary Rodham Clinton on September 11, 2012.
 His retirement ceremony was held at the U.S. State Department on Wednesday, July 1, 2015.
Joseph Edward Davies (November 29, 1876 – May 9, 1958) was an American lawyer and diplomat.
 He was appointed by President Wilson to be Commissioner of Corporations in 1912, and First Chairman of the Federal Trade Commission in 1915.
 He was the second Ambassador to represent the United States in the Soviet Union and U.S. Ambassador to Belgium and Luxembourg.
 From 1939 to 1941 Davies was Special assistant to Secretary of State Hull, in charge of War Emergency Problems and Policies.
 From 1942 through 1946 he was Chairman of President Roosevelt's War Relief Control Board.
 Ambassador Davies was Special Advisor of President Harry Truman and Secretary of State James F. Byrnes with rank of Ambassador at the Potsdam Conference in 1945.
Incumbency is one of the most researched and debated topics within the realm of political science.
 However, the research regarding appointed U.S. Senators and the incumbency advantage is not nearly as vast.
 In this research, the relationship between the number of months served as an appointed U.S. Senator and the percentage of vote that appointed senator receives in their initial election is studied.
 It is hypothesized that the longer an appointee has served before an election, the higher percentage of vote that appointee will receive.
 To do this, data was compiled from the United States congressional archives consisting of appointed U.S. Senators, the percentage of vote those appointed senators won in their election after their appointment, as well as the number of months served between their appointment and election.
 Discovering a relationship between months served and the vote percentages received will add to the scholarship of incumbency, and more specifically, how the discipline of political science views appointed U.S. Senators.
Zalmay Mamozy Khalilzad (Pashto: زلمی خلیلزاد "Zalmay Khalīlzād"; born March 22, 1951) is a former American diplomat and a counselor at the Center for Strategic and International Studies (CSIS) and president of Gryphon Partners and Khalilzad Associates, an international business consulting firm based in Washington, D.C. He was the United States Ambassador to the United Nations under President George W. Bush.
 He has been involved with U.S. policy makers at the White House, State Department and Pentagon since the mid-1980s, and was the highest-ranking Muslim American in the Administration of U.S. President George W. Bush.
 Khalilzad's previous assignments in the Administration include U.S. Ambassador to Afghanistan and U.S. Ambassador to Iraq.
 In 2017, he was considered for U.S. Secretary of State under the Presidency of Donald Trump.
Stuart W. Holliday is the President and CEO of the Meridian International Center, nonprofit organization that works with the U.S. Department of State, U.S. embassies, governments, public and private sector organizations, and leaders worldwide to promote global diplomacy, leadership development, educational, cultural exchanges, and diplomatic policy programs.
 Holliday is the former U.S. Ambassador for Special Political Affairs at the United Nations and Special Assistant to President George W. Bush, and Associate Director of Presidential Personnel.
John Van Antwerp MacMurray (October 6, 1881 – September 25, 1960) was an American attorney, author and diplomat best known as one of the leading China experts in the U.S. government.
 He served as Assistant Secretary of State from November 1924 to May 1925, and was subsequently appointed Minister to China in 1925.
 Although MacMurray had coveted the China post, he soon fell into disagreement with the State Department over U.S. policy towards the ruling Kuomintang government.
 He resigned the position in 1929 and briefly left the foreign service.
 Following several years in academia, MacMurray returned to the State Department to become Minister to Estonia, Latvia and Lithuania from 1933 to 1936.
 He later served as ambassador to Turkey from 1936 to 1941, and then was made a special assistant to the Secretary of State until his retirement in 1944.
David Wurmser (born in Switzerland) is an American foreign policy specialist.
 He served as Middle East Adviser to former US Vice President Dick Cheney, as special assistant to John R. Bolton at the State Department and as a research fellow on the Middle East at the American Enterprise Institute (AEI).
 He served in the U.S. Navy Reserve as an intelligence officer at the rank of Lieutenant Commander.