(NewsNation) — Presidential historian Allan Lichtman, who had predicted that Vice President Kamala Harris would win the 2024 presidential election against former President Donald Trump, mainly attributed his incorrect prediction to the proliferation of online misinformation and disinformation.

Lichtman, who had correctly predicted nearly every presidential race since 1984 using a formula of 13 true-or-false questions, cited the influence of social media platforms including Elon Musk’s X as one of the reasons he was wrong.

The American Univeristy professor said Monday on NewsNation’s “CUOMO” that “disinformation has exploded to an unprecedented degree. We’ve seen something brand new this time: Elon Musk putting his thumb on the scales through his control of X.”

Lichtman claimed misinformation on Musk’s platform received “billions of views” and affected every aspect of the election, from economic metrics to immigration policy and foreign affairs. He noted that 17% of voters incorrectly believed President Joe Biden was responsible for overturning Roe v. Wade.

During a livestream on election night, as the results were revealing a Trump victory, Lichtman repeatedly said, “I don’t get it.”

“Oh, the democracy’s gone,” Lichtman said as Trump was on his way to win major swing states. “Once democracy’s gone, it’s almost impossible to recover. The way to recover is by the dictators losing wars.”

Lichtman acknowledged he may need to adjust his prediction model, saying the premise that a “rational, pragmatic electorate” decides elections might need revision given the current information landscape.

“Maybe the premise of the keys needs to be changed,” Lichtman said. “I have four years to figure this out.”

Why Allan Lichtman predicted a Kamala Harris win

The historian who devised the “Keys to the White House” formula has correctly predicted nine of the last 10 presidential elections, including Trump’s victory over Hillary Clinton in 2016.

Lichtman confirmed several keys favoring Harris, including the short-term economy key (no recession in election year) and long-term economy key (per capita growth exceeding previous terms’ average).

While Democrats lost the party mandate key due to their 2022 House losses, Lichtman previously told NewsNation they salvaged the crucial party contest key by uniting behind Harris.

“Maybe the Democrats listened to me … they united overwhelmingly behind Harris, avoiding the loss of the contest key,” he said.

How does ‘Keys to the White House’ formula work

Developed in 1981 with mathematician Vladimir Keilis-Borok, Lichtman’s formula of 13 keys to the White House has helped him make overwhelmingly accurate predictions ever since.

He says that if the party holding the White House loses six of those keys, that party will probably lose the election.

Allan Lichtman’s keys to the White House:

Party mandate

Party contest

Incumbency

Third party

Short-term economy

Long-term economy

Policy change

Social unrest

Scandal

Foreign/military policy failure

Foreign/military policy success

Incumbent charisma

Challenger charisma

NewsNation’s Katie Smith contributed to this report.