WASHINGTON, DC - AUGUST 04: Former members of the U.S. military carry boxes representing more than 100,000 signatures requesting that Sen. John McCain (R-AZ) and other Republican leaders withdraw their endorsement of Republican presidential candidate Donald Trump following a press conference on Capitol Hill August 4, 2016 in Washington, DC. Trump has become embroiled in controversy since responding to the family of U.S. Army Capt. Humayun Khan who was killed while serving in the U.S. Army in Iraq in 2004. (Photo by Win McNamee/Getty Images)

WASHINGTON, DC - AUGUST 04: Navy airman 1st Class Nate Terani, the first Muslim to be selected to serve in the U.S. Navy Presidential Honor Guard, joins with other former members of the U.S. military to request that Sen. John McCain (R-AZ) and other Republican leaders withdraw their endorsement of Republican presidential candidate Donald Trump following a press conference on Capitol Hill August 4, 2016 in Washington, DC. Trump has become embroiled in controversy since responding to the family of U.S. Army Capt. Humayun Khan who was killed while serving in the U.S. Army in Iraq in 2004. (Photo by Win McNamee/Getty Images)

Retired US Navy Nuclear Machinist Mate 2nd Class Jim Lyons (C), alongside fellow veterans, carries empty boxes serving as a symbolic delivery of signatures on a petition calling for Senator John McCain(R-AZ) and other Republican leaders to withdraw their endorsement of Republican presidential nominee Donald Trump on August 4, 2016 on Capitol Hill in Washington,DC. The event is organized by military veterans, MoveOn.org and Common Defense PAC,and the signatures were actually delivered on a USB thumb-drive. / AFP PHOTO / SAUL LOEBSAUL LOEB/AFP/Getty Images

(L-R) US President Barack Obama and US Secretary of Defense Ashton Carter speak before a briefing at the Pentagon on August 4, 2016 in Washington, DC. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

(L-R) US Secretary of Homeland Security Jeh Johnson, US Secretary of the Treasury Jacob Lew, National Security advisor Susan Rice US Vice President Joe R. Biden, US President Barack Obama, US Secretary of Defense Ashton Carter, Chairman of the Joint Chiefs of Staff Joseph Dunford, and US Attorney General Loretta Lynch wait for a briefing at the Pentagon on August 4, 2016 in Washington, DC. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

(L-R) US Vice President Joe Biden, US President Barack Obama and US Secretary of Defense Ashton Carter wait for a briefing at the Pentagon on August 4, 2016 in Washington, DC. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

(L-R) US President Barack Obama and US Secretary of Defense Ashton Carter speak before a briefing at the Pentagon on August 4, 2016 in Washington, DC. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images

(L-R) US Vice President Joe Biden, US President Barack Obama and US Secretary of Defense Ashton Carter wait for a briefing at the Pentagon on August 4, 2016 in Washington, DC. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images