When political leaders face a constitutional crisis, like that of Jan. 6, the process of collectively deciding how to respond can be messy, arbitrary, and sometimes change the nature of the system itself.If you look for international parallels to the moment last year when Vice President Mike Pence refused to bow to pressure from President Donald J. Trump to help overturn their election defeat, something quickly becomes clear.Such crises, with democracy’s fate left to a handful of officials, rarely resolve purely on legal or constitutional principles, even if those might later be cited as justification.Rather, their outcome is usually determined by whichever political elites happen to form a quick critical mass in favor of one result. And those officials are left to follow whatever motivation — principle, partisan antipathy, self-interest — happens to move them.Taken together, the history of modern constitutional crises underscores some hard truths about democracy. Supposedly bedrock norms, like free elections or rule of law, though portrayed as irreversibly cemented into the national foundation, are in truth only as solid as the commitment of those in power. And while a crisis can be an opportunity for leaders to reinforce democratic norms, it can also be an opportunity to revise or outright revoke them.Amid Yugoslavia’s 2000 election, for example, the opposition declared it had won enough votes to unseat President Slobodan Milosevic, whose government falsely claimed the opposition had fallen short.Both sides appealed to constitutional principles, legal procedures and, with protests raging, public will. Ultimately, a critical mass of government and police officials, including some in positions necessary to certify the outcome, signaled that, for reasons that varied individual to individual, they would treat Mr. Milosevic as the election’s loser. The new government later extradited him to face war crimes charges at The Hague.Slobodan Milosevic, the former president of Yugoslavia, applauding during a passing-out ceremony of recruits at the military academy in Belgrade, in 2000. Mr. Milosevic was declared the loser of a disputed election, and later extradited to face war crimes charges at The Hague. Agence France-PresseAmericans may see more in common with Peru. There, President Alberto Fujimori in 1992 dissolved the opposition-held Congress, which had been moving to impeach him. Lawmakers across the spectrum quickly voted to replace Mr. Fujimori with his own vice president, who had opposed the presidential power grab.Both sides claimed to be defending democracy from the other. Both appealed to Peru’s military, which had traditionally played a role of ultimate arbiter, almost akin to that of a supreme court. The public, deeply polarized, split. The military was also split.The Themes of the Jan. 6 House Committee HearingsMaking a Case Against Trump: The committee appears to be laying out a road map for prosecutors to indict former President Donald J. Trump. But the path to any trial is uncertain.Day One: During the first hearing, the panel presented a gripping story with a sprawling cast of characters, but only three main players: Mr. Trump, the Proud Boys and a Capitol Police officer.Day Two: In its second hearing, the committee showed how Mr. Trump ignored aides and advisers in declaring victory prematurely and relentlessly pressing claims of fraud he was told were wrong.Day Three: Mr. Trump pressured Vice President Mike Pence to go along with a plan to overturn his loss even after he was told it was illegal, according to testimony laid out by the panel during the third hearing.At the critical moment, enough political and military elites signaled support for Mr. Fujimori that he prevailed. They came together informally, each reacting to events individually, and many appealing to different ends, such as Mr. Fujimori’s economic agenda, notions of stability, or a chance for their party to prevail under the new order.Peru fell into quasi-authoritarianism, with political rights curtailed and elections still held but under terms that favored Mr. Fujimori, until he was removed from office in 2000 over corruption allegations. Last year, his daughter ran for the presidency as a right-wing populist, losing by less than 50,000 votes.Modern Latin America has repeatedly faced such crises. This is due less to any shared cultural traits, many scholars argue, than to a history of Cold War meddling that weakened democratic norms. It also stems from American-style presidential systems, and deep social polarization that paves the way for extreme political combat.Presidential democracies, by dividing power among competing branches, create more opportunities for rival offices to clash, even to the point of usurping one another’s powers. Such systems also blur questions of who is in charge, forcing their branches to resolve disputes informally, on the fly and at times by force.Venezuela, once the region’s oldest democracy, endured a series of constitutional crises as President Hugo Chávez clashed with judges and other government bodies that blocked his agenda. Each time, Mr. Chávez, and later his successor, Nicolás Maduro, appealed to legal and democratic principles to justify weakening those institutions until, over time, the leaders’ actions, ostensibly to save democracy, had all but gutted it.Hugo Chavez, the former president of Venezuela, arriving at the National Assembly for his annual state of the union address in Caracas, Venezuela, in 2012. He and his successor appealed to legal and democratic principles to justify their weakening of democratic institutions.Ariana Cubillos/Associated PressPresidencies are rare in Western democracies. One of the few, in France, saw its own constitutional crisis in 1958, when an attempted military coup was diverted only when the wartime leader Charles de Gaulle handed himself emergency powers to establish a unity government that satisfied both civilian and military leaders.While other systems can fall into major crisis, it is often because, as in a presidential democracy, competing power centers clash to the point of trying to overrun one another.Still, some scholars argue that Americans hoping to understand their country’s trajectory should look not to Europe but to Latin America.Ecuador came near the brink in 2018 over then-President Rafael Correa’s effort to extend his own term limits. But when voters and the political elite alike opposed this, Mr. Correa left office voluntarily.In 2019, Bolivia fell into chaos amid a disputed election. Though the public split, political and military elites signaled that they believed that the incumbent, the left-wing firebrand Evo Morales, should step down, all but forcing him to do so.Still, when Mr. Morales’s right-wing replacement oversaw months of turmoil and then moved to postpone elections, many of those same elites pushed for a quick vote instead, which elevated Mr. Morales’s handpicked successor.Evo Morales, the former president of Bolivia, speaking to the press on election day in La Paz, Bolivia, in October 2019. The country fell into chaos after the election, which was disputed.Martin Alipaz/EPA, via ShutterstockThe phrase “political elites” can conjure images of cigar-chomping power-brokers, meeting in secret to pull society’s strings. In reality, scholars use the term to describe lawmakers, judges, bureaucrats, police and military officers, local officials, business chiefs and cultural figures, most of whom will never coordinate directly, much less agree on what is best for the country.Still, it is those elites who collectively uphold democracy day-to-day. Much as paper money only has value because we all treat it as valuable, elections and laws only have power because elites wake up every morning and treat them as paramount. It is a kind of compact, in which the powerful voluntarily bind themselves to a system that also constrains them.“A well-functioning, orderly democracy does not require us to actively think about what sustains it,” Tom Pepinsky, a Cornell University political scientist, told me shortly after the Capitol riot on Jan. 6, 2021. “It’s an equilibrium; everybody is incentivized to participate as if it will continue.”But in a major constitutional crisis, when the norms and rules meant to guide democracy come under doubt, or fall by the wayside entirely, those elites suddenly face the question of how — or whether — to keep up their democratic compact.They will not always agree on what course is best for democracy, or for the country, or for themselves. Sometimes, the shock of seeing democracy’s vulnerability will lead them to redouble their commitment to it, and sometimes to jettison that system in part or whole.The result is often a scramble of elites pressuring one another directly, as many senior Republicans and White House aides did throughout Jan. 6, or through public statements aimed at the thousands of officials operating the machinery of government.Scholars call this a “coordination game,” with all those actors trying to understand and influence how the others will respond until a minimally viable consensus emerges. It can resemble less a well-defined plot than a herd of startled animals, which is why the outcome can be hard to predict.Before Jan. 6, there had been little reason to wonder over lawmakers’ commitment to democracy. “It had not been a question of whether or not they supported democracy in a real internal sense — that had never been the stakes,” Dr. Pepinsky said.Now, a crisis had forced them to decide whether to overturn the election, demonstrating that not all of those lawmakers, if given that choice, would vote to uphold democracy. “I’ve been floored by how much of this really does depend on 535 people,” Dr. Pepinsky said, referring to the number of lawmakers in Congress.. More