​On a historic night where Hillary Clinton became the first woman ever to claim a major party presidential nomination, a Gold Star father became an unexpected center of attention for his impassioned endorsement of her candidacy.

Khizr Khan, whose son Humayun was killed by a suicide bomber in Iraq 12 years ago, turned his family's story of struggle and loss into a searing indictment of Republican presidential nominee Donald Trump.

"Hillary Clinton was right when she called my son 'the best of America,'" he told delegates at the Democratic convention in Philadelphia. "If it was up to Donald Trump, he never would have been in America."

Trump has made limiting immigration of Muslims into the United States a key promise on the campaign trail. Khan, who moved to America after growing up in Pakistan, decried those ideas as unpatriotic and offensive.

"Donald Trump, you are asking Americans to trust you with our future," he said, eliciting loud cheers from the crowd. "Let me ask you: Have you even read the U.S. Constitution? I will gladly lend you my copy. In this document, look for the words 'liberty' and 'equal protection of law.'"

Khizr Khan, whose son Humayun S. M. Khan was one of 14 US Muslims who died serving the United States in the ten years after 9/11 speaks during the final day of the 2016 Democratic National Convention on July 28, 2016, at the Wells Fargo Center in Philadelphia, Pennsylvania. / AFP / Robyn BECK (Photo credit should read ROBYN BECK/AFP/Getty Images)
Khizr Khan, whose son Humayun S. M. Khan was one of 14 US Muslims who died serving the United States in the ten years after 9/11 speaks during the final day of the 2016 Democratic National Convention on July 28, 2016, at the Wells Fargo Center in Philadelphia, Pennsylvania. / AFP / Robyn BECK (Photo credit should read ROBYN BECK/AFP/Getty Images)

Khizr Khan, whose son Humayun S. M. Khan was one of 14 U.S. Muslims who died serving the United States in the 10 years after 9/11, speaks during the final day of the 2016 Democratic National Convention on July 28, 2016, in Philadelphia.

Photo Credit: Robyn Beck/AFP via Getty Images

Humayun Khan, an Army captain, was one of 14 U.S. Muslims killed in action in the decade after the Sept. 11 attacks. Khan called Trump's campaign a constant smear against his family and their religious community.

"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. We can't solve our problems by building walls and sowing division."

Khan was part of a series of speakers on national security issues, which Democrats have tried to emphasize in the final days of their convention. Republicans have criticized Clinton as a weak and untrustworthy leader, while Democrats have portrayed Trump as an erratic and dangerous unknown.

Watch the full speech below:

Leo Shane III covers Congress, Veterans Affairs and the White House for Military Times. He can be reached at lshane@militarytimes.com.