A Texas Republican congressman has introduced a bill targeting immigrants who advocate for or have ties to socialist, Marxist, or Islamic fundamentalist movements, naming it directly after New York City's Democratic mayor.

Rep. Chip Roy (TX-21)officially introduced theMeasures Against Marxism's Dangerous Adherents and Noxious Islamists (MAMDANI) Act of 2026on 20 April, seeking sweeping amendments to the Immigration and Nationality Act. The legislation would make any non-citizen affiliated with or advocating for socialist, communist, Chinese communist, Marxist, or Islamic fundamentalist parties or doctrines inadmissible to the United States, deportable if already resident, and ineligible for naturalisation.

Its acronym is a deliberate reference toZohran Mamdani, the self-described democratic socialist who serves as mayor of New York City, whom Roy's office names directly in the bill's justification materials.

The bill, introduced into the 119th Congress and referred to committee, amends three key sections of existing immigration law. Under Section 212(a)(3)(D) of the Immigration and Nationality Act, the proposal would expand the current prohibition on admitting members of totalitarian parties to cover a specifically enumerated list: Chinese communist parties, communist parties, socialist parties, and Islamic fundamentalist parties. It also adds, for the first time, explicit grounds for inadmissibility for anyone who advocates or has ever advocated for those ideologies.

Deportation provisions run equally broad. The bill adds a new subsection to Section 237(a)(4) of the Immigration and Nationality Act that would render any non-citizen deportable if they have ever written, distributed, or even possessed material advocating for communism, Marxism, socialism, or Islamic fundamentalism.

🚨 JUST IN: Rep. Chip Roy is filing the "MAMDANI Act" to DEPORT and DENATURALIZE foreigners advocating for or linked to an Islamist, socialist, communist or Chinese communist partyYES! We need this!The bill also targets aliens belonging to organizations advocating for Islamic…pic.twitter.com/8t6DxitqSE

That same subsection applies to anyone who, at any time after their admission into the United States, joins or affiliates with any organisation the bill defines as falling under those categories.

The legislation also extends what is currently a ten-year bar on naturalisation for members of totalitarian parties to 20 years, and narrows the existing exception for involuntary membership by lowering the qualifying age threshold from 16 to 14. Under the bill's definitions section, 'socialism' is defined to include any movement that advocates the doctrines of Karl Marx or Friedrich Engels. 'Islamic fundamentalism' is defined to include any effort to advocate or impose Sharia law 'in any setting.'

The bill's title is not coincidental. Roy's office distributed a summary alongside the bill text arguing that 'the very presence of Zohran Mamdani and those like him who champion Marxist ideologies' demonstrates how the US immigration system 'enables the mass importation of Marxists and Islamists.'

Mamdani, born in Uganda in 1991 and raised in the United States, became a naturalised US citizen in 2018. He was elected mayor of New York City in 2025 and is a self-described democratic socialist.

Source: International Business Times UK