Before the 1970s, just once in 185 years had the House of Representatives proceeded toward formal impeachment of a president. In the past 45 years, the House has done so now three times. In fact, members of the House have introduced resolutions calling for consideration of articles of impeachment for seven of the past eight presidents.

Working to impeach a president is the height of institutional conflict: It shows that our national institutions cannot resolve major political struggles by regular means. So what changed — and what does it mean for the future?

How did the U.S. develop such a model of divided government?

This institutional propensity toward conflict grows from an old misunderstanding. As the U.S. framers wrote the Constitution, they took some inspiration from a recent — but not current — English model of separation of powers. During the 17th century, the king and Parliament had been fighting over which should prevail as the system shifted from absolute monarchy to a parliamentary regime. This mixed regime involved continuously strained interactions between the two powers. Parliament resisted the general tendency of the monarchy to absolutism and countered objectionable royal policies by removing — impeaching — the king’s ministers who were implementing them.

However, by 1789, when the framers signed the Constitution, the United Kingdom no longer worked that way. Some of the Founding Fathers’ main intellectual references, including John Locke and Baron de Montesquieu, had written about the English system of separation of powers several decades before.

Without today’s prompt communication technologies, the delegates to the Constitutional Convention didn’t have that updated information. They couldn’t know that, by the late 18th century, the United Kingdom was already a parliamentary regime with fusion of powers between the Parliament and the Cabinet, with both relying on the same political majority. Since 1730, Parliament had appointed the prime minister based on electoral results — which all but nullified the king’s executive power. And since the monarch hadn’t used the royal veto since 1707, the king’s legislative powers scarcely existed. With such a weak monarch, impeachment wasn’t necessary. In 1716, members of Parliament had stopped impeaching the king’s ministers — because Parliament had already curbed the king.

At the Constitutional Convention in Philadelphia, Alexander Hamilton proposed an “elected king,” appointed for life. But that’s not what the delegates adopted; they went with a model that was more mixed. Like a king, the president would control all executive power, but temporarily. When George Washington stepped down after two terms, he created an informal two-term limit that was later confirmed by a constitutional amendment. Like a king, the president could appoint his own cabinet, but Congress had to approve some chief officers. The president could also veto legislation, but Congress could potentially override it. And Congress could hold the president accountable through impeachment.

Certainly, the Constitution’s drafters knew that these separate sources of power could come into conflict. They included formulas that would favor cooperation between the executive presidency and the legislative majority, including the electoral college. But the framers made some miscalculations. Delegates in Philadelphia expected states would put forward a variety of candidates; none would win a national majority in the electoral college; and the election would typically pass to the House of Representatives.

The framers didn’t expect candidates to emerge and run nationwide. Nor did they expect that majority coalitions would be able to designate a winner in the electoral college, without the House’s review or intervention. What they thought they were constructing, with the legislature selecting the chief executive, would have been a parliamentary regime.

The president and the legislature could work together when the parties weren’t very unified. That’s over.

For many years, that didn’t matter. In periods of divided government, when the president’s party didn’t have a congressional majority, the conflict was attenuated — primarily because the political parties were not ideologically united and couldn’t easily discipline their elected members. Congress could build flexible legislative majorities around the president’s proposals, working across party lines.

But in the late 19th century and again after the 1960s, increasing polarization and stronger party discipline dominate. A divided government is no longer an opportunity for bipartisan cooperation; rather, it often leads to conflict between government branches that results in legislative paralysis. More and more, Americans see adversarial politics, confrontation, legislative gridlock and government shutdowns.

With such a polarized and partisan environment, impeachments grow more attractive.

In 17th-century England, the conflict between the executive and the legislative branches of government that came with a mixed regime and separation of powers resulted in civil war, temporary dictatorship, revolution, and finally, Parliament’s ascendancy. In the United States, the medium-term consequences of the current clash are hard to predict. But they might not be mild.

Josep M. Colomer has been a professor of political science of Georgetown University and is a life member of the American Political Science Association and the author, among many other books, of “The Science of Politics” (Oxford University Press, 2010).

Read more TMC analysis of the impeachment inquiry: