Since his six-minute speech at last summer’s Democratic Convention, Khizr Khan has become a kind of celebrity, an honorable everyman who stood up for America’s Muslim community. The story he told of his son Humayun, a captain in the U.S. Army who gave his life to stop a suicide bomber approaching his troops in Iraq, in 2004, was emotional, and it made for gripping television. The Washington Post called the image of Khan waving his pocket-size Constitution in the air—and asking if Donald Trump had ever read it—one of the most memorable of the campaign. “I will lend you my copy,” Khan said, addressing Trump. “You have sacrificed nothing and no one.” His speech made the Constitution a best-seller on Amazon. Google searches on it soared tenfold.

Khan, a Harvard-educated lawyer, was born in Pakistan; his son Humuyun was born in the United Arab Emirates. Both became U.S. citizens in 1986. On Sunday, Khan stopped by my house in Washington, and, over honey-lavender tea, discussed President Trump’s new executive order banning the entry of Syrian refugees indefinitely and all refugees for four months. The executive order suspends the entry of all citizens from seven predominantly Muslim countries—Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen—for ninety days. The order also calls for a general review of U.S. vetting procedures. The following interview has been edited and condensed for clarity.

What was your reaction to President Trump’s Executive Order?

It’s un-American. It’s against the safety of my country. I say to President Trump and his security advisers, the drafters of these executive orders, to get out of the White House and go to Arlington Cemetery and stand in front of all the tombstones and learn from observation that Muslims, and people from all other faiths, have given their lives to protect the Constitution and values of pluralism and equal protection. I hope that their sense of patriotism is awakened and they realize that these executive orders banning Muslims and creating walls will not do.

Do you have regrets about your personal loss in light of this action?

Not at all. If I had ten sons I would sacrifice them and offer them for the betterment of this country. We are direct beneficiaries of those values. It’s a tribute to the goodness of my country and to its values of inclusion and welcoming immigrants and people from hopeless parts of the world.

Some ugliness has been directed towards us. But we are grown-up people and we know how to forward ugliness to law enforcement.

Is there backlash among Muslims in the United States?

It alienates Muslims who are patriotic citizens. The Bush and Obama Administrations learned that alienating a large Muslim population in the United States works against keeping the U.S. secure. It makes people think of harm. Politicians had been joining hands with local Muslim communities to make them part of the solution rather than alienating them. Dealing with homegrown terrorism is not a one-step deal; an executive order does not solve the problem. It’s building relationships with the communities.

When a community at large feels alienated, bad elements start to rise. It’s the tragedy that has happened in Europe. It had failed to include immigrants from various parts of the world. Bad elements among them gained strength and began to think of harming societies.

The lone wolves?

Exactly.

How are Muslims elsewhere in the world reacting?

Internationally, it has given platform to our enemies. They are now telling the world’s more than 1.6 billion Muslims, “Haven’t we been telling you that America is at war with Islam?”

It puts the lives of our men and women serving in these countries in danger. Almost five thousand died in Iraq, where my son died. The coterie of people who surround Trump is so bent on their racist and Islamophobic agenda that they do not see the harm and danger that these executive orders are causing.

One of the first cases affected by the new executive order was an interpreter who worked with the U.S. military. Did your son work with local interpreters?

Yes. We have received not only letters but pictures of people who worked with him.

Ask any member of our defense forces serving in those countries—their lives depend on the loyalty of these people. I am worried about our sons and daughters serving in the countries across the world—these interpreters provide lifesaving advice.

President Trump’s national-security adviser, retired Lieutenant General Michael Flynn, has called Islam a “vicious cancer.” He said, “Fear of Muslims is rational.”

Mike Flynn’s rhetoric is unbecoming of a senior member of the armed forces in my country. His ignorance and hatred of a religion of many millions in the United States, and more than a billion in the world, speaks volumes of his ignorance and narrow-mindedness. It is Flynn and Stephen Bannon who have misguided Trump and brought us into the darkest period in U.S. history.

You spoke at the Democratic Convention but you’re not a lifelong Democrat. You supported Ronald Reagan.

I did. I supported Reagan from his first term and my support continued into his second term. I carried with pride the card I received when I contributed to the Reagan campaign. It had Lee Atwater’s signature on it. I have it still today. I also have a card with Reagan’s signature. I voted for Clinton, Obama, and Hillary based on what is good for my country.

What have you been doing since the Democratic Convention?

My speaking engagements include law schools, academic institutions, bar associations, Muslim organizations, middle schools, and high schools. The Oxford Union. And so many more keep coming.

What’s your message?

We are at a crossroads in our history. I urge every patriotic American to remain faithful and hopeful, and remain standing. Never before was your duty to serve your country more important, so we can dispel this momentary racism and dehumanization of mankind through these executive orders and bigoted threats.

When nations build walls they suffocate, and I will not let that happen until my last breath—as my son did.

What do you tell other Muslims now?

I tell Muslims to fully participate in the democratic process. It could be on public service boards, local county boards. Don’t be pushed into the corner. Run for office if you can. Participate in campaigns. Contribute to campaigns. I say this not only to Muslims. It is critical to Muslims, but I say it to all American patriots.

Participation doesn’t guarantee you success. Look at Abraham Lincoln. He continued to lose. [Over the course of his career, Lincoln was defeated when he ran for the Illinois state legislature, for the Speakership of the Illinois House, and for the nomination to run for Congress. He was also defeated twice in runs for the Senate, and lost a bid to be a Vice-Presidential candidate.] But he became President. Don’t be without a voice. Speak about the issues that affect your society.