Former President Donald J. Trump and his allies are not doing much to reassure those worried about his autocratic instincts. If anything, they seem to be leaning into the predictions.When a historian wrote an essay the other day warning that the election of former President Donald J. Trump next year could lead to dictatorship, one of Mr. Trump’s allies quickly responded by calling for the historian to be sent to prison.It almost sounds like a parody: The response to concerns about dictatorship is to prosecute the author. But Mr. Trump and his allies are not going out of their way to reassure those worried about what a new term would bring by firmly rejecting the dictatorship charge. If anything, they seem to be leaning into it.If Mr. Trump is returned to office, people close to him have vowed to “come after” the news media, open criminal investigations into onetime aides who broke with the former president and purge the government of civil servants deemed disloyal. When critics said Mr. Trump’s language about ridding Washington of “vermin” echoed that of Adolf Hitler, the former president’s spokesman said the critics’ “sad, miserable existence will be crushed” under a new Trump administration.Mr. Trump himself did little to assuage Americans when his friend Sean Hannity tried to help him out on Fox News this past week. During a town hall-style meeting, Mr. Hannity tossed a seeming softball by asking Mr. Trump to reaffirm that of course he did not intend to abuse his power and use the government to punish enemies. Instead of simply agreeing, Mr. Trump said he would only be a dictator on “Day 1” of a new term.“Trump has made it crystal clear through all his actions and rhetoric that he admires leaders who have forms of authoritarian power, from Putin to Orban to Xi, and that he wants to exercise that kind of power at home,” said Ruth Ben-Ghiat, author of “Strongmen: Mussolini to the Present,” referring to Vladimir V. Putin of Russia, Viktor Orban of Hungary and Xi Jinping of China. “History shows that autocrats always tell you who they are and what they are going to do,” she added. “We just don’t listen until it is too late.”Despite his public sparring with China’s leaders, President Trump has praised President Xi Jinping for his strongman policies.Erin Schaff/The New York TimesTalk about the possible authoritarian quality of a new Trump presidency has suffused the political conversation in the nation’s capital in recent days. A series of reports in The New York Times outlined various plans developed by Mr. Trump’s allies to assert vast power in a new term and detailed how he would be less constrained by constitutional guardrails. The Atlantic published a special issue with 24 contributors forecasting what a second Trump presidency would look like, many of them depicting an autocratic regime.Liz Cheney, the former Republican congresswoman from Wyoming who was vice chairwoman of the House committee that investigated the Jan. 6, 2021, attack on the Capitol, published a new book warning that Mr. Trump is a clear and present danger to American democracy. And of course, there was the essay by the historian, Robert Kagan, in The Washington Post that prompted Senator J.D. Vance, Republican of Ohio and a Trump ally, to press the Justice Department to investigate.To be sure, American presidents have stretched their power and been called dictators going back to the early days of the republic. John Adams, Andrew Jackson, Abraham Lincoln, Woodrow Wilson and Franklin D. Roosevelt, among others, were all accused of despotism. Richard M. Nixon was said to have consolidated power in the “imperial presidency.” George W. Bush and Barack Obama were both compared to Hitler.But there is something different about the debate now, more than overheated rhetoric or legitimate disagreements over the boundaries of executive power, something that suggests a fundamental moment of decision in the American experiment. Perhaps it is a manifestation of popular disenchantment with American institutions; only 10 percent of Americans think democracy is working very well, according to a poll in June by the Associated Press-NORC Center for Public Affairs Research.Perhaps it is a reflection of the extremism and demagoguery that has grown more prevalent in politics in many places around the world. And perhaps it stems from a former president seeking to reclaim his old office who evinces such perplexing affinity for and even envy of autocrats.Mr. Trump once expressed no regret that a quote he shared on social media came from Mussolini and adopted the language of Stalin in calling journalists the “enemies of the people.” He told his chief of staff that “Hitler did a lot of good things” and later said he wished American generals were like Hitler’s generals.Last December, shortly after opening his comeback campaign, Mr. Trump called for “termination” of the Constitution to remove Mr. Biden immediately and reinstall himself in the White House without waiting for another election. The former president’s defenders dismiss the fears about Mr. Trump’s autocratic instincts as whining by liberals who do not like him or his policies and are disingenuously trying to scare voters. They argue that President Biden is the real dictator because his Justice Department is prosecuting his likeliest challenger next year for various alleged crimes, although there is no evidence that Mr. Biden has been personally involved in those decisions and even some former Trump advisers call the indictments legitimate.“The dictator talk by Kagan and his fellow liberal writers is an attempt to scare Americans not just to distract them from the failures and weakness of the Biden administration but because of something they are even more afraid of: that a second Trump administration will be far more successful in implementing its agenda and undoing progressive policies and programs than the first,” Fred Fleitz, who served briefly in Mr. Trump’s White House, wrote on the American Greatness website on Friday.Mr. Kagan, a widely respected Brookings Institution scholar and author of numerous books of history, has a long record of support for a muscular foreign policy that hardly strikes many on the left as liberal. But he has been a strong and outspoken critic of Mr. Trump for years. In May 2016, when other Republicans were reconciling themselves to Mr. Trump’s first nomination for president, Mr. Kagan warned that “this is how fascism comes to America.”His essay on Nov. 30 sounded the alarm again. Mr. Trump may have been thwarted in his first term from enacting some of his more radical ideas by more conventional Republican advisers and military officers, Mr. Kagan argued, but he will not surround himself with such figures again and will encounter fewer of the checks and balances that constrained him last time. The former president’s defenders dismiss the fears about Mr. Trump’s autocratic instincts as complaints by liberals who are trying to scare voters.Jordan Gale for The New York TimesAmong other things, Mr. Kagan cited Mr. Trump’s effort to overturn an election that he had lost, disregarding the will of the voters. And he noted Mr. Trump’s overt discussion of prosecuting opponents and sending the military into the streets to quell protests. “In just a few years, we have gone from being relatively secure in our democracy to being a few short steps, and a matter of months, away from the possibility of dictatorship,” Mr. Kagan wrote.Mr. Vance, a freshman senator who has courted Mr. Trump’s support and was listed by Axios this past week as a possible vice-presidential running mate next year, took umbrage on behalf of the former president. He dispatched a letter to Attorney General Merrick B. Garland suggesting that Mr. Kagan be prosecuted for encouraging “open rebellion,” seizing on a point in Mr. Kagan’s essay noting that Democratic-run states might defy a President Trump.Mr. Vance wrote that “according to Robert Kagan, the prospect of a second Donald Trump presidency is terrible enough to justify open rebellion against the United States, along with the political violence that would invariably follow.”Mr. Kagan’s piece did not actually advocate rebellion, but simply forecast the possibility that Democratic governors would stand against Mr. Trump “through a form of nullification” of federal authority. Indeed, he went on to suggest that Republican governors might do the same with Mr. Biden, which he was not advocating either.But Mr. Vance was trying to draw a parallel between Mr. Kagan’s essay and Mr. Trump’s efforts to overturn the 2020 election. By the Justice Department’s logic in pursuing Mr. Trump, the senator wrote, the Kagan article could be interpreted as “an invitation to ‘insurrection,’ a manifestation of criminal ‘conspiracy,’ or an attempt to bring about civil war.” To make his point clear, he insisted on answers by Jan. 6.Mr. Kagan, who followed his essay with another on Thursday about how to stop the slide to dictatorship that he sees, said the intervention by the senator validated his point. “It is revealing that their first instinct when attacked by a journalist is to suggest that they be locked up,” Mr. Kagan noted in an interview.Aides to Mr. Trump and Mr. Vance did not respond to requests for comment. David Shipley, the opinion editor of The Post, defended Mr. Kagan’s work. “We are proud to publish Robert Kagan’s thoughtful essays and we encourage audiences to read both his Nov. 30 and Dec. 7 pieces together — and draw their own conclusions,” he said. “These essays are part of a long Kagan tradition of starting important conversations.”It is a conversation that has months to go with an uncertain ending. In the meantime, no one expects Mr. Garland to take Mr. Vance seriously, including almost certainly Mr. Vance. His letter was a political statement. But it says something about the era that proposing the prosecution of a critic would be seen as a political winner. More