DT, has proposed banning immigrants from Muslim-majority countries. Former House Speaker Newt Gingrich suggested that Muslims who believe in Shariah should be deported. And former New York City Mayor Rudy Giuliani said Muslims on the federal government's terrorism watch list -- a secretive and some say overly broad list -- should be forced to wear electronic bracelets to monitor their whereabouts.

Khan, whose son, Army Capt. Humayun Khan, 27, died from a suicide bombing in Baghdad 12 years ago, said Trump's shifting proposals to ban Muslims from entering the country would have prevented his late son from serving in the military. The Khans, originally from Pakistan, immigrated to the United States in the 1970s from the United Arab Emirates.

 "Have you ever been to Arlington Cemetery?" Khan asked Trump. "Go look at the graves of the brave patriots who died defending America -- you will see all faiths, genders and ethnicities. You have sacrificed nothing and no one."

In a particularly powerful moment of his speech, Khan pulled a pocket-sized Constitution from his suit jacket and held it in the air, and said:"Donald Trump, you're asking Americans to trust you with their future. Let me ask you, have you even read the United States Constitution?" he said. "I will gladly lend you my copy. In this document, look for the words, look for the words, liberty and equal protection (under) law."  And he shook his copy of the Constitution at Trump.