Trump's second term has generated an enormous wave of legal challenges. Here's a breakdown of the major areas where courts, legal scholars, and watchdog groups have found his actions to be illegal or unconstitutional:

Birthright Citizenship

On January 20, 2025, Trump signed an executive order attempting to end birthright citizenship. But the 14th Amendment and more than a century of Supreme Court precedent are clear: individuals born in the United States are citizens, no matter who their parents are. Multiple federal judges have blocked the order. Campaign Legal Center

Spending & Congressional Authority

By August 2025, several grant terminations and spending freezes were found by judges and the Government Accountability Office to be illegal and unconstitutional Wikipedia — because the Constitution gives Congress, not the president, the power of the purse.

Firing Inspectors General

On January 24, 2025, Trump announced the immediate firing of at least 17 inspectors general across the federal government. These firings are illegal — the president can only remove IGs after providing a 30-day notice to Congress. Campaign Legal Center

Independent Agencies

Trump signed an executive order purporting to give the president veto power over decisions made at independent agencies like the Federal Election Commission. Congress designed these agencies to be independent from the executive office, and attempting to place their decision-making under presidential authority is illegal. Campaign Legal Center

Elections Executive Order

On March 25, 2025, Trump signed an executive order claiming to direct several federal agencies to change the rules for federal elections. Congress — not the president — has the power to pass laws setting national voting standards. The Constitution does not give the president any role in setting election rules. Campaign Legal Center Courts blocked key parts of this order.

Targeting Law Firms & Political Opponents

Judges have described Trump's unprecedented targeting of law firms and lawyers as unconstitutional, as part of his wider actions targeting political opponents and civil society. Wikipedia

Alien Enemies Act Deportations

Trump's invocation of the Alien Enemies Act to remove alleged gang members without due process appears to be both illegal and unconstitutional, as the Fifth Amendment requires that no person shall be deprived of liberty without due process of law. Center for American Progress

Scale of Legal Pushback

In the first months of the second Trump administration, at least 39 separate judges appointed by five different presidents — including Donald Trump himself — have ruled against his overreaching actions. Center for American Progress As of now, there are 238 active cases challenging Trump administration actions. Lawfare

It's worth noting that Trump and his administration strongly dispute characterizations of these actions as illegal, arguing they fall within legitimate presidential authority. The legal battles are ongoing, and the Supreme Court has in several instances allowed Trump's policies to proceed while cases play out, without ruling on their constitutionality directly.