Massad Boulos is a Lebanese American businessman and the father-in-law of Tiffany Trump. Donald Trump named Boulos a senior adviser covering Arab and Middle Eastern affairs in December 2024. Boulos played a major unofficial role in the 2024 Trump campaign, courting Arab American voters. In September 2024, Boulos met with Mahmoud Abbas, the leader of the Palestinian Authority, on the sidelines of the United Nations General Assembly in New York. He also helped deliver a letter from Abbas to Trump in July 2024, in which Mr. Abbas wished Mr. Trump well after an attempted assassination that month. Boulos sought a seat in Lebanon’s Parliament in 2009 and described himself as a “friend” of a Lebanese presidential candidate who had received support from the militant group Hezbollah.