Today, Americans United and our allies told the U.S. Supreme Court that President Donald Trump’s Muslim ban is an unconstitutional violation of America’s fundamental promise of religious freedom.

Religious freedom is about fairness – we don’t treat people differently because their beliefs are different from ours, and we certainly don’t ban people from America based on their religion. But that’s just what Trump’s Muslim ban does.

On Oct. 10, the Supreme Court will hear arguments in two cases that challenge Trump’s Muslim ban – Trump v. International Refugee Assistance Project and Trump v. State of Hawaii. Americans United and our allies today filed a friend-of-the-court brief explaining to the Supreme Court that Trump’s Muslim ban is un-American and unconstitutional because it singles out a group of people for disfavor based solely on their religion.

“(B)y design and in actual effect the challenged Executive Order denigrates, maltreats, and fuels discrimination against Muslims, just for being Muslim,” the brief states. “This official denominational preference and the harms that it causes cannot be squared with the First Amendment’s guarantees of religious freedom.”

The Trump administration has tried to argue that its executive order barring immigrants from six Muslim-majority countries is about homeland security or immigration reform, but that’s a feeble attempt to mask the president’s true intent – discriminating against Muslims.

Trump repeatedly promised to ban Muslims while he was campaigning for president, and he has continued to make comments that show his anti-Muslim bias. His campaign vow for a “total and complete shutdown of Muslims entering the United States” remained on his website after his inauguration and wasn’t removed until after multiple federal courts blocked the Muslim ban citing that very statement.

The administration also has failed to prove that the Muslim ban somehow protects national security. Not only did Trump rely on political advisers rather than national-security experts to draft the executive orders, but his own Department of Homeland Security determined in February that citizenship is an “unreliable” basis for screening potential terrorists and that people from the countries targeted by the Muslim ban were “rarely” involved in terrorism in the U.S. In fact, no one from any of the banned countries has killed anyone in a terrorist attack on U.S. soil.

In the words of the 4th U.S. Circuit Court of Appeals when it ruled against Trump’s ban on May 25 in the Trump v. IRAP case, the ban “speaks with vague words of national security, but in context drips with religious intolerance, animus, and discrimination.”

President Donald Trump’s Muslim ban is an unconstitutional violation of America’s fundamental promise of religious freedom.

Even this summer, after the Supreme Court temporarily allowed the ban to go into effect for those who don’t have a “bona fide” or close familial relationship with people already in the U.S., Trump still tried to ban as many Muslims as possible by refusing to consider the grandparents, grandchildren and similar extended family relationships to be close. Thankfully, the Supreme Court intervened and ended Trump’s cruel “Grandma Ban.”

Rather that promoting national security, Trump’s Muslim ban and his rhetoric have inflamed anti-Muslim sentiment in the U.S. and put Americans at risk. Since January, when Trump signed the first executive order, there has been a more than 90 percent increase in anti-Muslim hate crimes compared to the same period last year. And 60 percent of American Muslims reported experiencing discrimination based on their religion in the past year.

“Government speech and official action have real, palpable force in telling people what conduct toward others is acceptable and what is not,” our brief to the Supreme Court states. “So when the government communicates that minority groups are objects of scorn who do not belong, private citizens are encouraged to treat them as such.”

That’s why Americans United and our allies continue to fight Trump’s Muslim ban. Religious freedom means that we all have the right to believe, or not, as we see fit. And it means that we don’t single out people for discrimination based on their religion.

“President Trump’s Muslim ban is anathema to the Constitution,” AU Legal Director Richard B. Katskee said. “When the Supreme Court hears this case next month, we urge the justices to come down on the right side of history by holding that the ban violates America’s fundamental promise of religious freedom.”

Joining AU in today’s brief are the religious and civil-rights organizations Bend the Arc: A Jewish Partnership for Justice, Lambda Legal Defense and Education Fund, People For the American Way Foundation and the Southern Poverty Law Center. Also joining are The Riverside Church in the City of New York and seven faith leaders from Colorado, Florida, Minnesota and New York.

You also can support AU's efforts. Tomorrow we’ll be emailing our supporters to encourage them to sign a pledge to support religious freedom in advance of this fall’s two vital arguments before the Supreme Court – the Muslim ban and Masterpiece Cakeshop v. Colorado Civil Rights Commission, which involves a bakery trying to use religion to justify discrimination against same-sex couples. Sign up for our emails so you can take the pledge and stay up to date on how you can help defend the separation of church and state.