New York — When Zohran Mamdani raised his right hand and took the oath of office as mayor of New York City, the ceremony itself followed a script older than the Republic. He pledged to uphold the Constitution of the United States, the New York State Constitution and the city charter, using language identical to that recited by generations of public officials.

What distinguished the moment was not the oath, but the book beneath his hand. Mr. Mamdani chose a Quran — a decision fully permitted under constitutional law — and one that nonetheless triggered an intense backlash in conservative media and pro-Trump online spaces within minutes of the ceremony.

The criticism was swift and emotional. Commentators framed the swearing-in as evidence of cultural decline, religious threat or ideological takeover, despite the absence of any procedural irregularity. Several prominent voices on the right described the event as “un-American,” even as legal scholars and historians noted that American law explicitly forbids religious tests for public office.

Article VI of the Constitution states that “no religious Test shall ever be required as a Qualification to any Office or public Trust under the United States.” Courts have long interpreted that protection broadly. Public officials have sworn oaths on Bibles, Qurans, law books or no book at all. John Quincy Adams used a volume of constitutional law. Theodore Roosevelt did not use a Bible. Atheists and members of minority faiths have served at every level of government.

None of those precedents altered the legal weight of the oath, which rests on the promise to uphold the law — not on the religious text used in the ceremony.

Still, the reaction underscored how symbols can eclipse substance in polarized politics. Critics of Mr. Mamdani did not point to policy actions — none have yet occurred — but to identity. The mayor, a Democratic socialist and a Muslim, became a lightning rod in a national culture war that has increasingly treated representation itself as provocation.

Supporters argue that the backlash says less about governance than about anxiety. New York City, home to more than eight million residents and one of the most religiously diverse populations in the world, has elected a leader whose biography reflects that diversity. For many voters, the moment was viewed not as rupture but as continuity — a routine transfer of power carried out under constitutional norms.

In his inaugural remarks, Mr. Mamdani focused on practical priorities: housing affordability, public transportation, childcare and municipal services. He made no reference to religion in outlining his agenda, emphasizing instead economic inclusion and infrastructure. His administration, he said, would be judged by outcomes, not symbolism.

The broader political context helps explain the intensity of the response. For years, former President Donald Trump and allied media figures have framed American politics around perceived threats to national identity, often linking immigration and religious difference to cultural loss. That framing has proven powerful among supporters — but it leaves little room for pluralism that operates plainly within constitutional bounds.

Legal experts note that the episode highlights a recurring contradiction. Many critics of Mr. Mamdani regularly invoke constitutional originalism and religious freedom. Yet those principles, applied consistently, protect his right to take office exactly as he did.

“This is not a gray area,” said one constitutional scholar. “The oath is valid. The ceremony was lawful. Discomfort does not equal illegality.”

The reaction also reveals how local events can take on national meaning. New York City is often cast as a cultural symbol — admired by some, resented by others — and its politics frequently become proxies for broader ideological struggles. In that sense, the backlash was less about municipal governance than about who is seen as entitled to lead.

Historically, such moments have occurred before. Catholic candidates once faced accusations of divided loyalty. Jewish officials encountered claims that they could not represent a Christian nation. Each controversy faded as familiarity replaced fear.

Whether this episode follows the same trajectory remains to be seen. For now, the practical reality is unchanged. The city continues to function. The mayor’s powers and constraints are defined by law. The Constitution remains intact.

What the moment exposed was not a breach of American norms, but a stress test of them — a reminder that constitutional protections matter most when they shield choices that some find unsettling.

As New York moves forward under its new leadership, the central question is unlikely to be about the book used at the inauguration. It will be about policy, performance and trust — the same measures by which every mayor, regardless of faith, is ultimately judged.