Donald Trump is like a brash club fighter who, in his first heavyweight bout, is staggering to his corner after a series of self-inflicted uppercuts. Trying to rouse Trump for the next round are sketchy handlers like Rudy Giuliani (who bizarrely forgot that 9/11 ever occurred) and the candidate’s rumored new debate coach, accused sexual harasser Roger Ailes.

With Hillary Clinton threatening to rack up the biggest electoral victory since George H.W. Bush obliterated Michael Dukakis in 1988, the scenarios for a comeback by the bilious billionaire are becoming increasingly far-fetched. In fact, the electoral prognosis for the Republican ticket is so dismal (Georgia and maybe even South Carolina are in play for the Democrats) that anyone working on the Trump transition team probably feels as superfluous as the Maytag repairman.

Barring a psychological transformation by Trump so amazing that it would rouse Sigmund Freud from his grave, it is hard to imagine anything that would defeat Clinton other than an “October Surprise.” Not just any surprise — but an external event so startling that it would scramble the political calculus.

The phrase “October Surprise” was originally coined during the 1980 campaign by William Casey, Ronald Reagan’s campaign manager and future CIA director. That citation was the definitive judgment of William Safire, the late New York Times columnist and epic chronicler of the idiosyncrasies of political language.

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Casey, as Safire recounted, was referring to the fear in the Reagan camp that the Iranians would at the last minute release the hostages from the American embassy takeover in an effort to throw the election to Jimmy Carter. In reality, the Iranians deliberately delayed the hostage release until minutes after Reagan was inaugurated in a final effort to humiliate Carter.

Long before the term “October Surprise” entered the lexicon, though, presidential elections were shaped by last-minute events.

The hard-fought 1884 election almost certainly was decided by a New York Protestant minister who, at a late October rally featuring GOP nominee James Blaine, castigated the Democrats as the party of “rum, Romanism and rebellion.” That intemperate comment, worthy of Trump, aroused Irish Catholic voters who handed New York State (by about 1,200 votes) and the election to Democrat Grover Cleveland.

Dwight Eisenhower probably would have romped home in a re-election landslide in 1956 even if Cold War global politics had not intervened. But in the final two weeks before the election, the world was upended not by one — but rather two — seismic events.

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The tragic Hungarian uprising (October 23) underscored the limits of American power to influence events behind the Iron Curtain. And in a military foray into Egypt that began on October 29, the Israeli army (in coordination with Britain and France) advanced to within 10 miles of the Suez Canal before the U.S. — breaking with its closest allies — helped impose a ceasefire.

After the horrors of 9/11, “October Surprise” morphed into a shorthand for a major terrorist attack on election eve. But now in the midst of the fourth presidential campaign since the Twin Towers toppled, we are returning to a more traditional definition of “October Surprise” as an unexpected outside event that influences voter behavior.

While predicting the nature of a campaign surprise is an oxymoron, the most likely contingency is Russian hacking of the internal files of the Clinton campaign or Clinton Foundation. A document dump on the eve of the election could leave voters reeling while the media struggles to definitively identify the hacker and the motivation.

Already, Russian hacking into the Democratic National Committee’s files has led to the forced resignation of Debbie Wasserman Schultz. And now Democrats are also dealing with the embarrassment that the files of the DCCC have also been compromised.

This kind of foreign finagling in American elections is unprecedented.

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The closest parallel that comes to mind was the October 1968 effort by Anna Chennault — an emissary from Richard Nixon’s campaign — to convince the South Vietnamese to scuttle any peace talks until after the election. When the Saigon government obediently balked, Lyndon Johnson railed on a White House tape that Nixon was guilty of treason.

But the Chennault conspiracy was an American-directed effort to manipulate a corrupt client state, South Vietnam. What the Russians are doing now is either a diabolical attempt to elect Trump or a towel-snapping effort to undermine Barack Obama’s political party.

The problem with hacking at this level is that it is virtually impossible to establish an ironclad connection to Putin — let alone the Trump campaign. Remember that in 1972, it was major feat of investigative reporting by Bob Woodward and Carl Bernstein to work out the linkage between the Watergate burglars and the Nixon campaign.

The threat of hacking is enough to make politicians (starting with Hillary Clinton) wish that email had never been invented.

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But you can’t blame all political embarrassments on technology. In the “rum, Romanism and rebellion” election of 1884, a letter surfaced linking Republican James Blaine with payoffs from railroad interests. At the end of the document, Blaine had scrawled, “Burn this letter.” No sure luck for Blaine and the Republicans.

Back in those days, it was muckraking newspaper publishers like Joseph Pulitzer who were publishing incriminating letters. It is far more frightening these days when political scandals are time-stamped, “Made in Moscow.”

Roll Call columnist Walter Shapiro is a veteran of Politics Daily, USA Today, Time, Newsweek and the Washington Post. His book on his con-man great-uncle was just published: “Hustling Hitler: The Jewish Vaudevillian Who Fooled the Fuhrer.” Follow him on Twitter @MrWalterShapiro .