President Trump’s critics warn that history will look unkindly on his effort to overturn a democratic election. This forecast, while understandable, may be wrong. History rarely looks on one-term presidents at all.

For the last four years I’ve covered his administration as a journalist while also researching and writing books about 19th-century American history. This made it natural to try assessing him from a distance, as future historians might peer at him. Someday the clamor of his tenure will fade, leaving behind a few essential facts, the first of which is his single term.

Few presidents who served four years or less find an enduring place in the popular imagination. One term is not long to influence a country so large and dynamic — and a president’s failure to win a second term can be a sign that he didn’t. If you are not from Indiana, you may not know my state produced Benjamin Harrison, a one-term president who was different from President William Henry Harrison, who died after one month in office. Few people visit the statue of James Buchanan in a lonely corner of a Washington park, and in my life I have met just one enthusiast for Chester A. Arthur.

One-term presidents who escape obscurity often did something beyond the presidency — like John Adams, one of the nation’s founders, or Jimmy Carter, whose much-admired post-presidency has lasted 10 times as long as his term. John F. Kennedy’s legacy rests, in part, on legislative achievements that passed after his assassination. Others are known for their failures while in office: Warren G. Harding for a corruption scandal, Herbert Hoover for economic calamity, Andrew Johnson for being impeached.

We can’t be sure what history will make of Mr. Trump, whose term featured scandal, impeachment and calamity, as well as a pandemic. His story may not be over; he remains at the head of a powerful movement, and reportedly talks of running in 2024. But to judge by information available today, he has a relatively narrow role in the American story: as the reaction to a game-changing president — Barack Obama.