During four years in office, President Trump has trampled political norms, attacked democratic institutions, sought to discredit government agencies, peddled baseless conspiracy theories and been impeached by the House.

Since his defeat in the November election, Trump’s critics have warned that his scorched-earth effort to invalidate the outcome amounts to a new level of danger: the first attempted coup d’etat in U.S. history to illegally maintain power.

The chorus of alarm grew this week after the disclosure that Trump bullied and threatened Georgia Secretary of State Brad Raffensperger in an hour-long private phone call Saturday, during which the president demanded that Raffensperger find thousands of votes for Trump that do not exist.

On social media, conservative and liberal pundits alike used the word “coup.” So did former George W. Bush aide Nicolle Wallace, Trump biographer Timothy L. O’Brien, political analyst Larry Sabato and Garry Kasparov, the Russian chess grandmaster and founder of the Renew Democracy Initiative. The Atlantic, the New Yorker, the Nation, Vanity Fair, New York magazine and the BBC have invoked the term to explore the ramifications of Trump’s assault on the nation’s democratic foundations.

In a phone call on Jan. 2, President Trump insisted he won the state and threatened vague legal consequences. Here are excerpts from the call. (Obtained by The Washington Post)

“If this isn’t an attempted coup then what is it?!” Charles M. Blow, a liberal columnist for the New York Times, asked on Twitter.

Historians described Trump’s actions as dangerous, irresponsible, harmful and unprecedented, but most said his behavior does not yet meet the formal academic definition of an attempted coup, which typically describes a military-backed effort to seize power from a legitimate government. Senior Pentagon officials have made clear that the military has no role in the fallout over Trump’s election defeat.

Trump has leveled baseless accusations of widespread election fraud, pressured the Justice Department to affirm his conspiracy theories, weighed appointing a legal ally as a special counsel to investigate his claims and privately discussed the efficacy of declaring martial law.

On Wednesday, some of Trump’s GOP allies on Capitol Hill will attempt to block congressional certification of President-elect Joe Biden’s 306-to-232 victory in the electoral college — two weeks before Biden is set to take the oath of office.

Trump’s strategy represents a brazen attempt to overturn or “steal” the election, historians and political scientists agreed. Some said he is tiptoeing toward an “autogolpe,” a Spanish term popularized in Latin America to describe a “self-coup” attempted by leaders who came to power legally and acted outside the law to try to maintain it.

“In technical terms, it’s probably not a coup. But it is an illegal and authoritarian attempt to stay in power,” said political scientist Steven Levitsky, co-author with fellow Harvard professor Daniel Ziblatt of “How Democracies Die,” which charts how democracies are more likely to fizzle through a slow but steady weakening of institutions.

Since the end of World War II, there have been 583 coup attempts across the globe, of which 288 were successful, according to new research for a forthcoming book, “Historical Dictionary of Modern Coups d’État.” About 96 percent were led by the military, while most of the others were carried out by civilian elites, said John Chin, research coordinator at the Institute for Politics and Strategy and one of the book’s co-authors along with Joseph Wright and David Carter.

Chin said the data are less reliable for autogolpes — which do not have an agreed-upon academic definition — but he estimated a separate 148 autogolpe attempts since 1946, of which 110 took place in autocracies and 38 in democracies. In most cases, the leader has attempted to suspend a constitution or discredit judicial or executive branches of government.

Only five times, Chin said, has a leader targeted an election winner, and in only one case did that happen in a democracy — in 1948, leading to the outbreak of the Costa Rican civil war.

Chin called Trump’s actions a “temper tantrum” but noted that the president does not have the support of military leaders or the business community. On Monday, more than 170 business executives signed a letter urging Congress to certify the election results. And the 10 living former U.S. defense secretaries, including Trump appointees Jim Mattis and Mark T. Esper, published an editorial in The Washington Post calling for a peaceful transition of power at the Pentagon.

“If this were a coup attempt, it’s perhaps the most bungled way to go about that I could imagine,” Chin said. “If Trump is really trying to stay in office after Jan. 20, he needs to be doing more than begging the Georgia secretary of state on Jan. 2 to do something.”

Naunihal Singh, a political scientist at the Naval War College, said that Trump’s blatant attempts to browbeat state officials and judges have succeeded foremost in revealing his own weak hand.

“The reason I don’t want to call it a coup is that it shifts the attention to the military,” said Singh, the author of “Seizing Power: The Strategic Logic of Military Coups.” “Everything he’s doing is precisely because of all his enablers.”

At a political rally Monday in Dalton, Ga., on behalf of Republican Sen. Kelly Loeffler and David Perdue — who were in Senate runoff contests with two Democrats on Tuesday — Trump told supporters that the pair would support his efforts to prevent Congress from certifying Biden’s win.

“For all of these people who think it’s too late, does that mean that we’re forced to approve a fraudulent election or an election with massive irregularities?” Trump said. “I don’t think so.”

A White House spokesman declined to comment for this report.

Yale historian Timothy D. Snyder pointed to Trump’s use of the National Guard to quell social justice demonstrations in Washington last summer as evidence that the president has deployed the military for political purposes.

In December, Trump allies, including former White House national security adviser Michael Flynn, urged the president to consider declaring martial law to “rerun an election” in several swing states. Later in the month, Trump met with Flynn and his lawyer, Sidney Powell, in the Oval Office, where they reportedly discussed the gambit, along with potentially installing Powell as a special counsel to investigate election fraud.

Neither idea has been carried out.

“The military is not up for it, but the fact that they’re not up for it doesn’t mean he’s not trying,” Snyder said. “People shy away from the term because Americans are generally exceptionalists and think a coup could only happen in foreign countries.”

Trump allies have sought to pressure local election boards, but they’ve faced resistance from key state-level officials, including some Republicans. The president’s lawyers have lost dozens of cases contesting the election results, including two lopsided defeats at the Supreme Court.

And several prominent GOP senators, including Majority Leader Mitch McConnell (Ky.), Mike Lee (Utah) and Tom Cotton (Ark.), have drawn Trump’s ire by announcing that they will not join the efforts to block certification of Biden’s win.

“This is more of a textbook case of democratic backsliding, which is less sexy of a term,” said Erica De Bruin, an assistant professor at Hamilton College and author of “How to Prevent Coups d’État.” Yet she emphasized that Trump’s strategy can be equally dangerous.

“When a coup happens, people can go on the streets and protest and there’s international condemnation,” she said. “But in this case, it’s harder to sustain opposition to what Trump is doing. And if Trump does not succeed, it’s easier for people to say the worries were overblown and dismiss it.”