Pregnant undocumented teenagers brought a class action lawsuit to challenge the Trump administration’s policy of preventing minors being held in immigration custody from obtaining abortions.

A Guantanamo detainee argued that several past rulings of the D.C. Circuit, in violation of Supreme Court precedent, have stripped Guantanamo detainees of due process protections during habeas proceedings in which they challenge their detentions. The detainee sought to have those past rulings overturned.

The federal government brought an antitrust case to try to block the merger of AT&T and Time Warner.

Numerous states, backed by utilities and trade groups, challenged the Obama-era EPA over its Clean Power Plan, a landmark set of regulations that restricted carbon dioxide emissions from coal-fired power plants. The Trump administration announced its intention to rescind the plan, and the court agreed to temporarily put the case on hold.

In December 2018, the Bureau of Alcohol, Tobacco, Firearms and Explosives issued a regulation banning “bump stock” devices, which are used to modify rifles so they can operate like automatic-fire weapons. Owners of bump stocks and other opponents of the regulation sued, arguing the ban violated the Administrative Procedure Act and the Fifth Amendment’s Takings Clause.

Andrew Miller, a former political aide, received a subpoena in connection with Special Counsel Robert Mueller’s investigation into Russian interference in the 2016 presidential election. Miller disobeyed the subpoena and argued that Mueller’s appointment as special counsel violated the Constitution’s Appointments Clause.

Technology companies, consumer advocates, and state attorneys general sued the Federal Communications Commission over its December 2017 repeal of net neutrality regulations.

Transgender service members sued the Trump administration over the constitutionality of a policy that bars trans people from serving openly in the military.

In 2014, the federal Medicare agency published a new legal interpretation that changed how Medicare reimbursements for hospitals were calculated. Hospitals hurt by the change challenged the interpretation because the agency did not conduct formal rulemaking. The D.C. Circuit agreed with the hospitals, and the Supreme Court granted cert to decide whether formal rulemaking was required.

A Guantanamo detainee challenged his continued detention on the basis that the original conflict in Afghanistan, which created the military’s initial authority to detain him, is now over.

An investment banker was charged with securities fraud, and the D.C. Circuit found that he had committed a “fraudulent scheme” arising from misleading statements to potential investors. The Supreme Court granted cert to determine whether, under SEC Rule 10b-5, conduct that does not meet the elements of a fraudulent “statement” can form the basis of liability for a fraudulent “scheme.”

The Catholic Church brought a First Amendment challenge over the D.C. transit authority’s refusal to run a religious-themed advertisement on the sides of city buses.

Farmers in India sued a component of the World Bank after it financed a power plant that polluted the local water supply. The D.C. Circuit held that the suit was barred by a doctrine that grants immunity to entities classified as “international organizations.” The Supreme Court granted cert to resolve the scope of that immunity doctrine. On Feb. 27, 2019, the Supreme Court reversed the D.C. Circuit in a ruling that limited the scope of immunity for international organizations and revived the Indian plaintiffs’ lawsuit.

The Trump EPA sought to delay implementation of an Obama-era rule that was intended to protect against chemical disasters. Environmentalists and states challenged the delay, arguing that the agency was using inaction to informally rescind the rule without going through formal rulemaking.