U.S. President Joe Biden's decision to not seek a second term has upended the 2024 presidential race, leading to an unpredictable and possibly chaotic nominating process with few parallels in modern U.S. history.
Biden announced Sunday he would step aside and endorsed his vice president, Kamala Harris, succumbing to weeks of pressure from Democratic Party colleagues concerned about his age and mental fitness.
Biden’s decision isn’t unprecedented. Presidents Lyndon B. Johnson in 1968 and Harry S. Truman in 1952 also started re-election bids and then withdrew from the race.
However, both of those men dropped out much earlier in the election cycle, giving their parties more time to reorganize and strategize for the general election.
In contrast, Biden’s withdrawal came after the primary voting process had concluded, and less than a month before the Democratic National Convention, where he was set to be formally nominated.
No U.S. presidential candidate has ever dropped out so late in the race, said Peter Loge, a professor at George Washington University, who called Biden’s decision “absolutely historic.”
“The U.S. political system isn’t like most of the rest of the world. Our elections are endless – and endlessly expensive,” Loge said. “Suddenly it feels like we’re having a snap election in the way that they’ve had in the U.K. recently.”
While Biden's exit set off a last-minute scramble to appoint a new nominee, senior Democratic Party leaders quickly tried to coalesce around Harris.
In the hours after Biden’s withdrawal, a wide range of high-profile Democrats, including some who had been seen as potential presidential contenders, endorsed Harris, saying it was important that the party unite to defeat former president Donald Trump, the Republican Party nominee.
Sufficient support for Harris could prevent a scenario known as an open convention, in which there is no predetermined nominee at the start of the gathering. Some observers warn such an outcome could be highly divisive and uncontrollable.
“Perhaps you don’t want a convention that is completely open because it tears the party apart, as opposed to rallying around one particular candidate,” said Gary Schmitt, a political scientist and senior fellow at the American Enterprise Institute.
“The next few days are pretty critical [in terms of] how much the Democratic pollsters and donors rally behind Harris or not,” he added.
In normal years, almost any uncertainty regarding a party’s presidential pick is resolved before its convention.
Since the 1970s, the conventions have been preceded by a series of state-by-state elections, known as primaries, which effectively determine the party’s presidential nominee.
To win the nomination, a presidential candidate must secure a majority of party delegates, who are apportioned according to the outcome of each state’s primary.
Those delegates then attend the convention, where they effectively ratify the voters’ choice.
As a result, party conventions have become tightly scripted, made-for-TV events, with passionate political speeches and celebrity performances typically overshadowing the largely perfunctory presidential nomination process.
However, when Democratic delegates gather in Chicago on August 19, the details may matter.
The overwhelming majority of Democratic Party delegates – about 3,900 – had already been secured by Biden. But after Biden dropped out, his delegates will now be freed to support whomever they choose. In an open convention scenario, any candidate would be eligible to run if they can first secure the signatures of 300 delegates.
All delegates would then participate in a first round of voting. If no candidate receives a majority of delegates, the convention would head to an even more contentious setup known as a “brokered convention,” in which candidates and influential party figures attempt to win over delegates during mostly private negotiations.
However, some reports suggest the party may attempt to avoid that outcome by holding a virtual vote or by finding another way to essentially lock in Harris or another candidate as the nominee before the convention.
In a statement Sunday, the Democratic National Committee, which organizes the convention, vowed a “transparent and orderly process,” which will be governed by “established rules and procedures.”
Depending on the outcome, there are potential concerns about legitimacy. For the first time in decades, a presidential nominee will not have been chosen directly by voters.