NEW YORK (Reuters) - Nazar Naqvi has faithfully voted Republican for more than three decades.

The grave marker of U.S. Army Captain Humayun Khan stands with the symbol of Islam on it amongst other grave markers inside of Section 60 in Arlington National Cemetery on Memorial Day, May 30, 2016. REUTERS/Lucas Jackson

After Donald Trump’s feud with Muslim parents who lost a son in battle for the United States, he has vowed not a single Republican will get his vote.

Naqvi, 69, a retired U.S. government engineer from Newburgh, New York, is a member of a small community of Muslims who are among America’s Gold Star families, those whose loved ones were killed while serving in the U.S. military.

His son Mohsin Naqvi, who was born in Pakistan, enlisted in the U.S. Army four days after Sept. 11, 2001, and was killed in 2008 by a roadside bomb in Afghanistan.

Trump lashed out at Khizr and Ghazala Khan, the Pakistani American parents of slain U.S. Army Captain Humayun Khan, after they appeared at last week’s Democratic convention in Philadelphia to criticize the Republican presidential hopeful for proposing a temporary ban on Muslims entering the country.

“I’m going to vote for anyone but Republicans because of this one person, this man who has gone out of his mind,” Naqvi said this week. “Not any office should get our vote. He has been nominated not by one person - the Republican Party nominated him.”

Naqvi said he was pressing his registered Republican friends to do the same.

The Pentagon says that 3,939 active duty service members have identified themselves as Muslim, less than 1 percent of the 1.3 million active duty U.S. military troops, but a Pentagon spokesman said there is no record of how many Muslims have been killed in action.

Reuters reached out to a dozen Muslim Gold Star families who lost a loved one in action after Sept. 11, 2001.

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The families are not organized as a group and some did not want to talk. But those who did agreed that Trump’s comments upended their political loyalties, and moved them to take action to register and motivate other voters to keep Trump out of the White House in November.

Nooshin Razani, 43, an Iranian-American pediatrician in Oakland, California, whose 19-year-old brother Omead Razani died while serving as a U.S. Army medic in Iraq in 2004, said Trump’s comments sparked her to speak to the press for the first time.

“When I saw there was this person who was willing to use religion in this negative way, I decided I’m coming forward,” said Razani.

Trump rebuked Khizr Khan for suggesting that he should read the U.S. Constitution and said his wife Ghazala may have stood silently by her husband because she might not have been “allowed” to speak.

Although Trump did call their son a hero and said his aim was to end radical Islamic terror, the ensuing uproar has caused many Republicans to distance themselves from him and to support the Khan family.

Razani joined more than 20 Gold Star families in signing an open letter calling for Trump to apologize to the Khans and said she is going to volunteer to register voters, mainly because of Trump’s comments about Ghazala Khan, which she said insulted all Muslim women.

“I want to be an active part of making sure people’s voices are heard. Even people Trump thinks don’t speak up,” Razani said.

Trump’s ongoing dispute with the Khans has become a call to political action for Kevin Ahearn of Phoenix. His brother, Army Major James Ahearn, converted to Islam to marry a woman with whom he fell in love in Iraq, brought to the United States and with whom he had a daughter before he was killed by a bomb in Iraq in 2007.

Kevin Ahearn, 48, said on Tuesday that he and his husband planned to go to Democratic Headquarters in Phoenix to volunteer for the first time.

“It makes me all the more determined that he does not make it to the White House,” said Ahearn, whose Muslim niece now is 10.

The soldier’s mother said she was shocked by Trump’s rhetoric and wishes she could talk to her late son about it.

“He was always a staunch Republican because they backed the military. I can’t imagine how he would feel now,” said Constance Ahearn, 75, who lives in the San Francisco area.