The American presidency is an office of immense power, but it is not a throne. The Constitution, through its brilliant and deliberate system of checks and balances, places firm limits on the executive. Yet throughout our history, some presidents have strained against those limits, testing the very foundations of our republic.
This is not a list of unpopular policies or political scandals. It is a sober, constitutional look at those rare and dangerous moments when a president’s actions created a genuine constitutional crisis by challenging, ignoring, or attempting to shred the rule of law. These are the moments that have tested the resilience of the framers’ design.
5. Abraham Lincoln and the Suspension of Habeas Corpus (1861)
The Constitutional Test: At the outset of the Civil War, President Lincoln unilaterally suspended the writ of habeas corpus, allowing for the military arrest and detention of suspected Confederate sympathizers without trial.
The Constitutional Crisis: The Constitution (Article I) states that the privilege of the writ of habeas corpus can be suspended “when in Cases of Rebellion or Invasion the public Safety may require it.” However, this power is listed in the article defining Congress’s powers. Chief Justice Roger Taney, acting in his circuit court capacity, ruled in Ex parte Merryman that only Congress could suspend the writ. Lincoln defied the ruling, arguing his wartime duty as Commander-in-Chief gave him the authority, creating one of the most debated and profound clashes between executive power and individual liberty in American history.
4. Richard Nixon and the Power of the Purse (1973)
The Constitutional Violation: President Richard Nixon, frustrated with a Democratic Congress, simply refused to spend billions of dollars that Congress had lawfully appropriated for programs he opposed, including for environmental protection and public housing. This practice, known as “impoundment,” was a direct assault on the separation of powers.
The Constitutional Crisis: Article I of the Constitution gives Congress the exclusive “Power of the Purse.” The President’s duty is to “take Care that the Laws be faithfully executed,” which includes spending the money Congress allocates. Nixon’s actions were a claim that the President could exercise a line-item veto over any spending law he disliked, a power the Constitution does not grant. The crisis was so severe that it led Congress to pass the Impoundment Control Act of 1974 to explicitly forbid the practice, a law that remains a crucial check on presidential power to this day.
3. Andrew Johnson’s Defiance of Reconstruction (1866-1868)
The Constitutional Violation: In the fragile years after the Civil War, President Andrew Johnson actively used his executive power to subvert the will of Congress and its plans for Reconstruction. He repeatedly vetoed landmark Civil Rights legislation and, in a final act of defiance, violated the Tenure of Office Act by firing his Secretary of War, Edwin Stanton, without Senate approval.
The Constitutional Crisis: This was a direct and unprecedented war between the President and a co-equal branch of government. Johnson was not merely disagreeing with Congress on policy; he was actively obstructing the execution of the laws it passed to protect the rights of newly freed slaves. His actions were such a profound violation of the separation of powers that they led to him becoming the first president in American history to be impeached by the House of Representatives, surviving removal by the Senate by just a single vote.
2. Barack Obama’s Use of Executive Action on Immigration (2012)
The Constitutional Violation: After Congress failed to pass the DREAM Act, President Barack Obama took unilateral action, creating the Deferred Action for Childhood Arrivals (DACA) program by executive memorandum. This new policy granted a form of legal status and work authorization to hundreds of thousands of undocumented immigrants who had been brought to the country as children.
The Constitutional Crisis: This was one of the most significant tests of the limits of executive power in modern history. Critics argued that the President was not merely exercising prosecutorial discretion – the power to decide who to deport – but was single-handedly creating a new immigration law, a power that belongs exclusively to Congress under Article I. The action, while driven by a desire to solve a difficult humanitarian problem, was a major expansion of the “pen and phone” presidency and remains a source of intense constitutional debate, with its legality still being challenged in the courts over a decade later.
