Since being ejected from the Oval Office in 1980, Jimmy Carter has spent his days conducting rogue diplomacy in global hot spots, dashing from the embrace of one dictator to another and generally making life miserable for sitting American presidents.

For this, Mr. Carter is often called our greatest ex-president.

Accordingly, his latest round of unauthorized diplomacy with Hamas will surely only enhance his post-presidential resume.

But truth be told, no amount of hobnobbing with terrorists or international do-goodery at the expense of American interests will ever erase Mr. Carter’s miserable legacy as president.

From his disastrous handling of both the Iran hostage and OPEC-generated oil crises, to agitated swamp rabbits in Plains, Ga., and cardigan sweaters in the Oval Office, his term was a malaise-inducing era that saw the gradual decline of American power and influence and the continued post-Watergate marginalization of the presidency.

Given this record of non-accomplishments, it is unsurprising that Mr. Carter has worked so fervidly to rehabilitate his record — and diminish the records of his successors.

He merely is following the precedent of other similarly failed leaders in the fraternity of America’s worst presidents.

Franklin Pierce, whose fumbling administration and Confederate sympathies paved the way for southern secession, was unable even to capture his party’s nomination for reelection in 1856 — the only sitting president to suffer this indignity. His time in office was considered such a failure that the citizens of his hometown of Concord, N.H., decided not honor the former president with a parade when he returned from Washington in 1857.

Pierce remerged from retirement when the Civil War erupted, training his fury on Abraham Lincoln, whom he blamed for the nation’s splintering. In a speech given days after the conclusion of the battle of Gettysburg in 1863, Pierce called the conflict a “fearful, fruitless, fatal civil war … prosecuted on the theory of emancipation, devastation and subjugation,” adding “… how futile are all our efforts to maintain the Union by arms.”

After Lincoln’s assassination in 1865, an angry mob surrounded Pierce’s house in Concord and demanded he prove his loyalty to the Union. It is said that the Pierce Manse escaped destruction only because the former president’s on-the-spot oratory soothed the angry mob. Pierce died in 1869. It was not until 1946 that a marker was placed on his grave in Concord’s Old North cemetery.

Pierce’s successor, James Buchanan, sat idly by as the nation fragmented and ultimately left the matter of disunion and Civil War in Lincoln’s lap. Buchanan left office disgraced in 1861.

Worried about how history would view his presidency, he wrote the first presidential memoir, “Mr. Buchanan’s Administration on the Eve of the Rebellion,” in 1866. While the book served as a memoir of his presidency, it was also Buchanan’s attempt to assuage his own guilt for the Civil War. In it, Buchanan claimed, “Every discerning citizen must now have foreseen serious danger to the Union from Mr. Lincoln’s election.”

Shortly before dying, Buchanan is reported to have said, “history will vindicate my memory.” Today, more than 150 years later, Buchanan, like Pierce, is still ranked among our worst presidents.

Blamed, perhaps unfairly, for the Great Depression, Herbert Hoover was turned out of office in favor of Franklin Roosevelt in 1932. Bitter and disappointed at the decline of his political fortunes, Hoover spent much of the following decade criticizing Roosevelt and the New Deal, whose programs Hoover would describe in his memoirs as “fascist measures.”

Hoover would remain active in humanitarian and charity work until his death at 90 in 1964, but to this day he remains a political boogeyman, conjured up each election cycle to show a candidate’s supposed economic ineptitude.

In 1789, George Washington, evoking Cincinnatus who resigned his post as Roman consul to resume his life as a citizen-farmer, let go of the reigns of power and returned home to Mount Vernon to live the rest of his days away from the public stage. Most of our great leaders have followed his example. John Adams returned to Peacefield, Thomas Jefferson to Monticello, James Madison to Montpelier … the list goes on.

Prime examples of the legacy in the modern era are Harry Truman, who gladly returned home to Independence, Mo., after his time in office and George H.W. Bush, who has largely avoided the political arena since being denied reelection in 1992 — quite a feat considering his eldest son has been at the center of American politics for most of the last decade.

Instead, it is usually America’s less accomplished leaders, fretting about their own place in history, who insist on remaining in the public eye and sabotaging their successors.

Of these men, Mr. Carter has been most malignant, attacking and undermining every president from Ronald Reagan to George W. Bush, whose administration Mr. Carter recently referred to as the “worst in history.”

It would be wise for Mr. Carter to wait until history casts its judgment on Mr. Bush.

Posterity, however, already has deemed Mr. Carter’s presidency a failure. If there is any justice, his post-presidency will be seen the same way.

Mr. Cole is a writer based in Washington, D.C.