According to the logic of punditry, history repeats itself, so every presidential election year must resemble a previous presidential election year. And the 2020 general election campaign is already being shaped by several colossal events—including widespread civil rights protests, an uncontained pandemic and an abrupt economic collapse—helpfully giving us political commentators plenty of fodder for making historic parallels. All we have to do now is figure out which year 2020 is copying, and we’ll know who is going to win. At least, that’s the idea.

So which one is it?

1968 has quickly become the focal point for many hot takes, as the ongoing nationwide protests sparked by the death of George Floyd recall the uprisings that followed the assassination of the Rev. Martin Luther King Jr. But even if it is 1968, it’s not clear which candidate would benefit.

Fox Business Network’s Stuart Varney argues what happened in 1968, when Richard Nixon’s “law and order” message resonated with the “silent majority,” bodes well for Donald Trump because “presidents who pledge to bring back the rule of law win.”

Historian Joshua Zeitz, writing for Politico, offered the counter-argument: 1968-style chaos is bad for the incumbent’s party. “Nixon’s law-and-order message wasn’t just about urban riots. It was a repudiation of the governing party for its alleged part in the general unraveling of peace, prosperity and order,” says Zeitz. He concludes, “Trump campaigns like Richard Nixon and George Wallace, but in reality, he is Lyndon B. Johnson: a man who has lost control of the machine.”

Without saying so directly, both Varney and Zeitz allude to two key differences between 1968 an 2020: Vietnam and Wallace. Fifty-two years ago, the Democratic Party coalition shattered because the antiwar left excoriated the Democratic Party’s nominee, Vice President Hubert Humphrey, for being complicit in Johnson’s escalation of the Vietnam War, while the segregationist Democrats broke away from the party because of Johnson and Humphrey’s leadership in passing the Civil Rights Act of 1964. Wallace’s third-party bid captured those wayward Democrats, winning five Southern states and snagging more votes than Nixon’s margin of victory in another 17 states.

Today, America is not stuck in a military quagmire. Nor is there a robust third-party candidacy driving a wedge through a major party. And Humphrey’s presence points to a third difference: Lyndon Johnson’s decision not to run for reelection. No incumbent’s name was on the ballot that year, as Donald Trump’s will be in November.

1920 is also in the running. At least, Democrats hope so. That year, Americans had a divisive, unpopular and largely incapacitated president (after suffering a stroke in the fall of 1919) in Woodrow Wilson. The beginning of Wilson’s presidency was marked by robust progressive reforms. But he eventually, and controversially, took America into the Great War. Once the war ended in late 1918, Wilson failed to address the resulting economic disruption, which contributed over the next several months to thousands of labor strikes and violent racial conflict in several cities. A spate of left-wing domestic terrorist bombings prompted an erosion of civil liberties led by Wilson’s attorney general. The country had also been laid low by a viral pandemic, the devastating 1918 Spanish flu, although the worst of it was over by 1920. With so much anxiety and uncertainty in the electorate, the progressivism embodied by Wilson had lost credibility.

Like LBJ, Wilson was not on the ballot, but the Democrat ticket was closely associated with his unpopular administration. And the Republican nominee, Sen. Warren Harding, offered a clear contrast by campaigning for a “return to normalcy.”

The Democrats’ fancy is that 100 years later, Trump is a Republican version of Wilson, with Joe Biden embodying a Harding-esque return to normalcy.

1980 might be a better parallel, one of only three election years in the 20^th century when an elected incumbent president was defeated in seeking a second term. The man in the Oval Office was Jimmy Carter, a Democratic Party outsider who narrowly won the presidency in a fluky election to end an eight-year GOP hold on the presidency. Carter was felled by an awful economy and a debilitating foreign policy challenge—the Iran hostage crisis—that was unsolved by Election Day. Ultimately, voters concluded he was in over his head.

Trump risks being felled by an awful economy and a debilitating global public health challenge that almost surely will be unsolved by Election Day. But he appears determined not to repeat one of Carter’s political mistakes: the “Rose Garden Strategy.”

Carter had something that Trump did not: a serious primary challenger in Ted Kennedy. And once Iranian revolutionaries took 52 Americans hostage, Carter kept Kennedy at bay by refusing to hit the campaign trail for several months while he focused on negotiating with the Iranians. That decision had the unintended effect of intensifying focus on the crisis, and that focus fed a perception of Carter’s ineptitude.  Remaining in the White House may have been a diligent course of action, but it didn’t give Carter any leverage. Afterwards, Carter said, “I think the issue would have died down a lot more if I decided to ignore the fate of the hostages, or if I decided just to stop any statements on the subject.”

Trump, in contrast, has been eager to campaign during the pandemic, and stir up controversies on a whole range of topics. He’s doing public events even though the still-circulating coronavirus makes such activity dangerous. Clearly, he does not want to echo Carter, and make his schedule subject to the whims of his enemy, visible or invisible. At the same time, he is vulnerable to the same perception that felled Carter: that he simply isn’t up to the job.

1832 could be the year 2020 most resembles – but only if Trump is able to win reelection. That was the year Andrew Jackson was seeking a second term. Like Trump, Jackson was a cantankerous, crude populist disliked by the Washington elite, some of whom expected the incumbent to lose. And like Trump, Jackson was dealing with a pandemic.

The cholera epidemic hit America well before it had the Centers for Disease Control and Prevention, and many looked to God for relief. Jackson’s Whig Party opponent, Henry Clay, sponsored a congressional resolution for a national day of fasting and prayer. But Jackson, who had a Jeffersonian view of the Constitution, refused to “disturb the security which religion now enjoys in the country in its complete separations from the political concerns of the General Government.” Historian Joyce Chaplin credits Jackson with indirectly encouraging a “shift toward secular and civic solutions to epidemics.” Jackson’s response to cholera wasn’t a major factor in his reelection, but his populist resistance to any political pressure from elites certainly was.

Trump has been criticized for not following the advice of scientific experts and pressuring states to prematurely reopen the economy. But if the coronavirus is more contained than many expect by the fall, Trump might receive credit from the public and revitalize his campaign, just in time.

1876 is the election year both parties fear 2020 will become. The vote totals were disputed in three former Confederate states where, in the Reconstruction Era, Republicans controlled the state election boards. Republicans accused Democrats of intimidating black voters. Democrats accused Republicans of stuffing ballot boxes and suppressing the votes of illiterate Democrats through trickery. After each state produced two competing sets of results, Congress created a special commission to come up with a solution. Eventually, a deal was struck, giving the Electoral College to the Republican, Rutherford D. Hayes, in exchange for the removal of federal troops from Southern states. This is ruefully remembered today as the moment when the Reconstruction Era ended and the Jim Crow Era began.

This year, both parties are already voicing concerns about fraud or disenfranchisement. Democrats are attacking Republicans for refusing to support mail-in voting and help people exercise their democratic rights during the pandemic. Trump and other Republicans are smearing mail voting as inherently ripe for fraud. In all likelihood, we will have a patchwork system in place, and in a close race, the party on the short end will have incentive to claim the system was corrupted. And there won’t be an obvious bargaining chip, like the end of Reconstruction, to secure bipartisan support for the final outcome. Any dispute will likely end up at the Supreme Court, and whether the public will broadly accept how it rules is a huge unknown.

In the end, perhaps the most obvious candidate is 1932, when the Great Depression incinerated Herbert Hoover’s presidency and sent him to a landslide defeat. As the nation’s unemployment hurtles towards Depression-era levels, Joe Biden’s lead in the RealClearPolitics average at the end of last week hit 8.1 percentage points. That’s a bigger lead than either Hillary Clinton in 2016 or Barack Obama in 2012 ever reached in the general election phase of their campaigns. Incumbent presidents—from Martin Van Buren to George H. W. Bush—just don’t do well when economies sputter, and if things don’t get better for America, things are highly unlikely to get any better for Trump.