INDEPENDENCE, Mo. — Donald Trump faces a far more formidable foe than whomever the Democrats nominate to face him in his reelection campaign.

His danger: History is written by academics and intellectuals, a group that, at least today, largely reviles the president and deplores the disruptions that he has sent coursing through the country and the global betrayals of long-term American interests they believe he has prosecuted. Trump is in for a rough time, with scathing assessments from historians who will pillory him for his coarseness, his penchant for divisive discourse and his status as one of only three presidents branded with the black mark of impeachment.

That’s in the short term — say, the next two decades. Then everything could change.

Trump is the first president since John F. Kennedy not to lean repeatedly on Harry Truman, who left office with low approval ratings and with the disdain of the commentariat and the academy. That’s one of the mysteries of the Trump presidency. Today Truman is a national hero, and now that his presidential library here is closed for a major expansion and renovation, Kurt Graham, the library’s director, speaks with a straight face about a phenomenon he calls “Tru-mania.”

That’s a big contrast from the mocking assessment offered by Doris Fleeson, the first female syndicated political columnist: “I wonder what Truman would do if he were alive,” she wrote when Truman still was alive. Those actual words have been invoked in complete, nostalgic seriousness for decades when Americans turned to Truman in a “WWHD” moment as they struggled with foreign-policy challenges, faced domestic labor disputes, or came up against just plain political foolishness.

“Truman swore,” Victor Davis Hanson of Stanford’s Hoover Institution wrote in National Review. “He had nightly drinks and played poker with cronies. And he shocked aides and the public with his vulgarity and crass attacks on political enemies. Truman mocked the widely respected Sen. William Fulbright as ‘half-bright.’”

Then there is John Quincy Adams, who ascended to the White House through a “corrupt bargain” and who was chased out of office by Andrew Jackson. Ten admiring biographies of the sixth president have been published in the last 22 years, plus a boxed set of his diaries published in 2017 by the prestigious Library of America and a separate 2017 biography of Adams’ wife, Louisa.

“In an era when the public’s regard for party politics has cratered,” the Princeton historian Sean Wilentz wrote in The Atlantic last spring, “historians’ estimation of the anti-party Adamses has soared higher than ever.” Writing in The Wall Street Journal, Drexel University dean and English professor Paula Marantz Cohen saluted Adams as “the metaphorical father of a nation whose character he ... tried to shape, often against fierce resistance.”

The lesson: Former presidents govern in the past. Their reputations are made in the future.

Two Democratic heroes, Thomas Jefferson and Jackson, make the point. The two were celebrated until recently, with state Democratic parties holding lavish Jefferson-Jackson Day dinner fundraisers. Today, with the two men’s reputations in retreat — one criticized as a hypocrite on race issues, the other vilified as an instrument of genocide against native peoples — nearly a dozen state parties have renamed their fundraisers.

This phenomenon is widespread. Woodrow Wilson, once a shining symbol of American idealism, today is regarded as a mushy-headed romantic and a racist. Dwight Eisenhower, once regarded as a sleepwalking through his presidency, has been re-evaluated as a subtle sage, with leading historians celebrating him as the “hidden-hand” president, a characterization from the late Princeton historian Fred I. Greenstein.

Trump’s courtship of constitutional crises by defying congressional demands has given a minor rehabilitation, at least by contrast, to Richard Nixon. A major question: Does that have the potential of softening the conventional view of Andrew Johnson, who last spring was flayed for having “disregarded Congress, whose legitimacy he ignored” in Barbara Wineapple’s account of the 1868 impeachment battle and was criticized by the historian Jon Meacham in “Impeachment: An American History” for being “an obstinate president” who fostered “fears that the grand American experiment in democracy was coming to an end”?

Former Gov. William F. Weld of Massachusetts, a member of the staff of the House impeachment committee during Watergate and the lone Republican challenger to Trump, said in an interview that in comparison to the president, Nixon was “a scion of the law.”

Alvin Felzenberg, who has written a book on the evaluations of presidents, believes that presidential reputations are framed by contemporary politics. “I suspect that Jackson — and Wilson and, maybe Truman, FDR and LBJ — may take a few tumbles when the question of executive versus congressional prerogatives is considered,” he said.

Trump’s presidential work ethic has the potential of adjusting our views of his predecessors.

“Sometimes it’s actually academic research that changes peoples’ views of presidents,” said Barbara Trish, a political scientist who teaches a course on the American presidency at Iowa’s Grinnell College. “But our current experience with presidents affects how we look at recent presidents, too. Donald Trump’s work ethic has made us think again about whether Ronald Reagan and George W. Bush were lazy.” (Both A. Scott Berg, in his 2013 biography of Wilson, and Patricia O’Toole, in her 2018 volume, noted how much the 28th president played golf, even amid grave crises. Reagan joked when he was leaving office that his chair in the White House Cabinet Room should carry the inscription: “Ronald Reagan Slept Here.”)

Both George H.W. Bush and Gerald R. Ford were awarded the Profiles in Courage Award from the John F. Kennedy Library. Reagan, whose Simi Valley, California, presidential library opens with a quote redolent of his optimism (“America’s best days are to come. Our proudest moments are yet to be”), is remembered, even by his critics, for buoyancy and cheerfulness, qualities in short supply in our time. “You don’t have to be a conservative to acknowledge that he changed the country and ended up changing the world,” said Kenneth M. Duberstein, Reagan’s last White House chief of staff.

Winston Churchill wrote of his father in 1906 that Lord Randolph Churchill “had the showman’s knack of drawing public attention to everything he said and did.” The same may be said of the current president. What will be said of Donald Trump in the decades to come is completely unknown.