While Democratic leadership continues to flinch at confrontation, the American Civil Liberties Union has become the most consistent and aggressive legal adversary of Donald Trump’s second-term agenda. With a growing list of lawsuits targeting nearly every major front of Trump’s policy regime—from immigration to healthcare to free speech—the ACLU is stepping into the vacuum of opposition.

1. J.G.G. v. Trump – Deportation Under the Alien Enemies Act

In one of the ACLU’s most urgent filings, the group is challenging the administration’s invocation of the 1798 Alien Enemies Act to carry out mass deportations of alleged Venezuelan gang members. The Trump administration argues the act allows expedited removal during “national security emergencies.” The ACLU counters that this 18th-century law was never intended for peacetime application and is being weaponized to sidestep due process.

The suit points to blanket raids, lack of individualized hearings, and the denial of asylum rights as constitutional violations. Immigration advocates argue it sets a dangerous precedent for expanding executive deportation powers beyond congressional limits.

2. Orr v. Trump – Banning Gender Marker Changes on Passports

Filed in February, this case challenges a new State Department policy that blocks transgender, nonbinary, and intersex individuals from changing gender markers on federal documents. The ACLU asserts that the policy violates First and Fifth Amendment rights, specifically targeting transgender Americans for discriminatory treatment.

Unlike previous cases under earlier administrations that hinged on bureaucratic delays, the ACLU argues this policy is intentionally punitive—a deliberate attempt to erase gender diversity from public life.

3. Fast-Track Deportation Expansion

The ACLU is representing organizations like Make the Road New York in their challenge to expanded fast-track deportation rules. These changes allow federal agents to deport undocumented immigrants without a court hearing if they cannot prove they’ve been in the U.S. for two years.

The suit argues this policy deprives people of legal representation, violates due process, and targets vulnerable communities, including those fleeing violence or natural disasters. Plaintiffs warn that the rule encourages racial profiling and expands unchecked federal power.

4. Guantánamo Bay Detentions

Perhaps the most shocking revelation this year is that immigrants have reportedly been transferred from U.S. soil to detention at Guantánamo Bay. The ACLU, alongside Las Americas Immigrant Advocacy Center, filed suit after being denied access to clients who were moved offshore.

Legal experts warn this could revive the Bush-era precedent of extrajudicial detainment, this time applied to civilians and immigrants rather than terrorism suspects. The administration has refused to disclose how many detainees are held at the facility, sparking alarm from human rights observers.

5. ACLU v. NEA – Anti-LGBTQ Censorship in the Arts

In March, the ACLU sued the National Endowment for the Arts for implementing an executive order barring grants to organizations that “promote gender ideology.” LGBTQ+ theater groups and artists were among the first to lose funding.

The lawsuit accuses the administration of violating First Amendment rights and enforcing an ideological litmus test for public funding. The ACLU calls it “a blatant attempt to censor queer expression under the guise of fiscal responsibility.”

6. Trans Youth Health Care Ban

An executive order signed in early February blocks federal funds to any institution providing gender-affirming care to minors. The ACLU filed suit immediately, stating the order is not only unconstitutional but actively harmful to youth already facing political and medical discrimination.

Doctors, parents, and young people have joined the case as plaintiffs. Medical organizations warn the ban is forcing clinics to close and driving trans youth to the brink.

7. Birthright Citizenship Rollback

Trump’s January executive order reinterpreting the 14th Amendment seeks to deny birthright citizenship to children of undocumented immigrants. The ACLU swiftly filed suit, calling the order unconstitutional, racist, and legally illiterate.

The complaint invokes both Supreme Court precedent and the plain language of the Constitution. Legal analysts suggest the case could be one of the most consequential of the Trump era, with implications for millions of American-born children.

8. DEI Firings and Political Purges

In a final ongoing lawsuit, the ACLU is backing a group of federal employees fired over participation in diversity, equity, and inclusion programs. These dismissals followed Trump’s February executive order banning DEI “indoctrination” in federal agencies.

The lawsuit claims the firings are political, retaliatory, and illegal under civil service protections. With Republicans attacking DEI on every front, this case could define whether ideological purges are permitted within the U.S. government.

While Democratic officials issue press releases and appeals to civility, the ACLU has become the de facto opposition. In courtrooms across the country, it is civil rights attorneys—not senators or party leaders—standing between Trump’s regime and what remains of constitutional rule.