Fundamentals

Impeachment: What It Is, How It Works, and Its Limits

By Daniel Sardá · Published on October 08, 2026

6 min read1,274 words

Impeachment is a constitutional mechanism for holding certain high officials accountable. Its legitimacy depends on effective checks as well as rules, evidence, and the right to defend oneself.

Impeachment is an extraordinary constitutional mechanism for holding certain high officials accountable. It may result in their removal from office and, depending on the country, disqualification from holding public office. It is not, however, a criminal trial conducted by politicians, nor is it a formal-sounding name for any attempt to remove a ruler.

Precision matters because there is no universal procedure. Each constitution determines who may be impeached, on what grounds, which body brings the accusation, who decides, what majority is required, and what the consequences are. A news story about impeachment in the United States therefore does not automatically describe what would happen in Argentina, Mexico, or another constitutional system.

Key idea: “Political” identifies the kind of responsibility at issue, the institutional purpose, and often the body that decides. It does not mean that the process may dispense with rules and become a mere partisan struggle.

What is impeachment for?

Its central purpose is to protect the constitutional order and the public interest from serious conduct by people in especially important offices. It is an exceptional form of oversight: it can address situations in which an official’s continued service is incompatible with the duties of office, even where the conduct under review does not necessarily amount to a criminal offense.

In that sense, the mechanism belongs to modern constitutionalism and its limits on political power. A person who exercises public authority does not receive a blank check. Yet neither should the majority overseeing that person possess unlimited power to remove them merely because it is expedient.

That tension explains the design of impeachment. A system that is too weak may enable impunity; one without safeguards may facilitate purges of opponents or recast an ordinary political disagreement as an alleged constitutional violation. Its value lies not only in allowing officials to be removed, but in subjecting that decision to defined powers and rules known in advance.

How impeachment usually works

Procedures differ, but it is useful to think of three stages: accusation, defense, and decision. This map offers orientation; it does not replace reading the applicable constitution.

1. A formal accusation

The process begins when the competent body brings charges against an official who is among those subject to impeachment. The accusation opens the process: it does not by itself establish responsibility or amount to removal from office.

In some bicameral systems, the functions are divided. The Argentine Constitution, for example, assigns accusation to the Chamber of Deputies and trial to the Senate. The United States Constitution uses a comparable division: the House of Representatives approves articles of impeachment, while the Senate conducts the trial, as the U.S. Senate explains.

2. Review of the charges and defense

The accused official must know the charges and have a genuine opportunity to answer them and challenge the evidence. The precise form of that defense varies by country and need not reproduce every rule of a criminal court.

Still, calling a process political does not eliminate procedural guarantees. In Constitutional Court v. Peru, the Inter-American Court of Human Rights held that the parliamentary proceeding it examined had violated due process, including because of problems involving the defense, evidence, and impartiality.

3. A decision with institutional effects

The final decision belongs to the body and requires the majority established by the relevant legal order. Some constitutions require supermajorities; others organize the procedure differently. A rule from one country should not be transferred to another.

When impeachment succeeds, its characteristic effect is to remove the official from office. It may also entail disqualification, but neither its duration nor its automatic application is universal. Acquittal or an insufficient number of votes, meanwhile, does not necessarily make every political criticism untrue; it means only that the mechanism did not produce a judgment under its own rules.

Impeachment and criminal trials are not the same

The most important difference lies in the question each procedure answers.

• Impeachment determines responsibility connected to the exercise of office and produces institutional consequences, such as removal.
• A criminal trial determines whether a person committed an offense and may impose penalties such as imprisonment or a fine.
• The former is usually conducted before political bodies defined by the constitution; the latter belongs to courts of law.
• Their grounds, standards, and procedures need not coincide.

The same conduct may give rise to both tracks, but neither automatically replaces the other. The Argentine Constitution makes the point clearly: it limits an impeachment judgment to removal and possible disqualification, while leaving the person subject afterward to accusation and trial in the ordinary courts.

Essential distinction: losing office is not the same as receiving a criminal conviction. Likewise, the absence of a proven crime does not by itself settle whether there was a constitutional violation or misconduct covered by the legal order.

Similar institutions worth distinguishing

Everyday language often blends institutions that serve different functions. Before drawing conclusions about a particular crisis, it is worth asking which institution the country’s constitution actually regulates.

Impeachment. The term broadly refers to a constitutional process for holding high officials accountable. In U.S. constitutional usage, however, it technically refers to the accusation approved by the House of Representatives; the subsequent trial takes place in the Senate. Being impeached does not mean that a person has been convicted or removed.

Removal of immunity or authorization to proceed. In general, these mechanisms lift a protection or satisfy a requirement so that criminal justice can proceed. They do not themselves determine criminal guilt. The Mexican Constitution, for example, regulates impeachment and the declaration of procedural admissibility separately.

Vote of no confidence. This is chiefly associated with the relationship of confidence between parliament and government in parliamentary systems. Its logic is to withdraw political support from the government, not to replicate impeachment against a particular official. In Spain, moreover, a motion of censure must propose an alternative candidate for prime minister.

Political accusation. A party, legislator, or citizen may publicly accuse an authority. That is part of democratic debate, but it does not necessarily initiate a constitutional proceeding or produce its legal effects.

What makes the mechanism legitimate

Legitimacy does not arise from putting the word “trial” in its name or assembling just any majority. At a minimum, it requires a competent authority, pre-established grounds, intelligible charges, an opportunity for defense, and serious examination of the evidence. Public proceedings and a separation between the body that accuses and the body that decides can also reduce abuse, though they do not by themselves guarantee neutrality.

These limits protect more than the accused official. They protect citizens from two opposite risks: a powerful ruler placed beyond all oversight, or a temporary majority using an exceptional power to eliminate opponents. Impeachment can serve its purpose only within a broader system of limits on political power.

In short: accountability and the right to defend oneself are not competing obstacles. Together, they distinguish constitutional oversight from arbitrary removal.

A practical question for every case

When impeachment appears in the news, the useful question is not merely who is accusing whom. Identify the applicable rule, the specific charges, the deciding authority, the safeguards available, and the possible effects. It is also important to distinguish each stage: investigating is not accusing; accusing is not convicting; removing someone from office is not imposing a criminal penalty.

Seen this way, impeachment is neither an automatic solution nor a democratic anomaly. It is an exceptional instrument for making public accountability effective. Its legitimacy depends precisely on the power to remove an authority also being limited by law.