Six months ago, Joe Biden’s legislative agenda was stalled, his approval rating was stuck in the 30s and three-quarters of Democrats wanted someone else to be the party’s nominee in 2024. But since then, things have really turned around for the president: He signed several big pieces of legislation, many of which passed with bipartisan support; his approval rating rose from the 30s to the 40s; and Democrats fared surprisingly well in the midterm elections. With this string of successes, the Democratic Party has re-coalesced around Biden. Should he decide to run for reelection, it’s all but certain that the Democratic nomination would be his.
Most signs indicate that Biden does indeed want to run again. He’s said that it’s his “intention” to run, and recent reports from Politico and The Hill say that he could make that official as soon as mid-February. But even so, there are reasons to think that Biden might ultimately choose to step aside rather than run for reelection. The president’s age is clearly catching up to him, and that’s only going to accelerate. By the end of a hypothetical second term, Biden would be 86 years old. Biden is also well known as a family man, and he may decide that he wants to spend his twilight years surrounded by family and grandchildren rather than army generals and political advisers.
Given that possibility, it’s worth taking seriously what would happen if Biden did step away—what chain of events would this set off? What would an incumbent-less 2024 Democratic primary look like? Who would be most likely to win that primary, and how would they fare in a general election?
Lessons From 1952 and 1968
To try to answer these questions, let’s first turn to history. Since the end of World War II, only two presidents have decided not to run for a second term—Harry Truman in 1952 and Lyndon Johnson in 1968. Though it’s quite a small data set, there are unambiguous similarities between the two men, why they decided to step down and the political reverberations of their respective decisions.
First, Truman and Johnson were both very unpopular presidents. Truman had led the country through the end of World War II, but by the time he was considering running for reelection in 1952, the United States was mired in yet another war, this time in Korea. On top of this, Truman’s administration was riddled with charges of corruption and communist infiltration—the latter being spun up by Sen. Joseph McCarthy and his fellow red-baiters on the House Un-American Activities Committee.
Johnson, for his part, had broken his promise not to widen America’s involvement in Vietnam. While his predecessor, John F. Kennedy, had kept America’s role to mostly advising and supplying South Vietnam, Johnson shifted the burden of fighting onto American soldiers in a process that became known as “Americanization.” By 1967, nearly 500,000 Americans were overseas in Vietnam, and in that year alone, the war killed more than 11,000 American soldiers. The final straw for many Americans came in January of 1968, when North Vietnamese forces launched a major escalation of the war, the Tet Offensive, which showed Americans that they weren’t as close to victory as Johnson had made it seem.
Unpopularity led to the second thing that Truman and Johnson both had to contend with: surprisingly strong primary challenges from mavericks within their own party. In 1952, Truman faced off against Tennessee Senator Estes Kefauver, who had earned national fame as the head of a Senate committee that investigated and exposed organized crime in the United States —including among Democratic Party bosses and political machines. According to polling at the time, he was among the ten most-admired men in America. And so when the nation’s first primary rolled around in New Hampshire, Kefauver scored an upset victory against the incumbent president. Soon after that defeat, with his popularity and polling tanking, Truman announced he wouldn’t be running for reelection.
Johnson’s story is nearly identical. He, too, faced a primary challenge from a party maverick in Minnesota Senator Eugene McCarthy, who harnessed the public’s frustration at Johnson’s handling of Vietnam. Running a single-issue campaign against the war, McCarthy became the clear choice for the “Dump Johnson” wing of the Democratic Party. As had happened 16 years earlier, things came to a head in New Hampshire: McCarthy earned 42% of the vote to Johnson’s 49%. This strong performance for the outsider exposed Johnson’s weaknesses. After three weeks of sinking poll numbers that followed the New Hampshire debacle, and facing the prospect of an embarrassing defeat, Johnson finally withdrew.
This brings us to the third factor that both 1952 and 1968 share: Although both Truman and Johnson were initially challenged by insurgents, Democrats eventually settled on establishment figures as their nominees in both years. An important bit of context is that, up until 1972, the presidential nomination process was nothing like it is today. Plenty of states didn’t even hold primaries and in most of those that did, the results did not bind their delegates to the winning nominee. In essence, nominees were chosen in smoke-filled rooms during the national party conventions, and state primaries acted more as a suggestion than anything conclusive.
Kefauver, who had made himself unpopular among Democratic leaders by exposing the party’s corrupt underbelly, had a distinct disadvantage in these smoke-filled rooms. So while he had gone on from New Hampshire to dominate the rest of the primaries, the party leaders ended up selecting the establishment-friendly governor of Illinois, Adlai Stevenson.
The outcome of the 1968 primary was similar. After McCarthy’s upset in New Hampshire and Johnson’s withdrawal, Robert Kennedy jumped into the race to compete with McCarthy for the support of the anti-war wing of the Democratic Party. Meanwhile, Vice President Hubert Humphrey avoided the primaries and instead tried to win over party leaders and convention delegates through wheeling and dealing. It’s anybody’s guess what would have happened had Kennedy not been shot and killed on the night of his big victory in California. But as it happened, with his death, the anti-establishment movement’s energy disappeared, and Humphrey became the clear frontrunner. He clinched the nomination at the convention with the support of the party establishment despite having not run in the primaries.
The fourth and final similarity between 1952 and 1968 is that the incumbent president’s party lost in both general elections. Truman’s successor Adlai Stevenson lost to the popular war hero Dwight Eisenhower in a crushing landslide. Sixteen years later, Richard Nixon defeated Hubert Humphrey in a much narrower victory. This is, in good part, because Stevenson and Humphrey got the worst of both worlds: Neither benefited from the advantages of incumbency, but at the same time, each had to answer for the president’s unpopular actions. In the end, the public’s discontent and desire for change were too great for Stevenson and Humphrey to overcome.
What This Means for 2024
What lessons can we take from these historical precedents, and what do they tell us about 2024? While it’s important not to exaggerate how much we can extrapolate from just two examples, there are nevertheless a few key points we can extract from the history book and apply to Biden and 2024.
First, incumbent presidents typically only choose not to run if they are facing an extreme political failure and if that failure spurs a strong primary challenge and intense intraparty division. Taking this at face value, we would expect Biden to run for reelection: He doesn’t have any failures on the books that get close to the Korean or Vietnam Wars, and he is not facing an internal Democratic revolt or insurgent primary challenge.
The caveat to this is that there is a clear reason why Biden might step back from running that has not applied as sharply to any president before him: his advanced age. On the day of his inauguration in 2021, Biden immediately became the oldest president in American history at the age of 78. The runner-up, Reagan, ended his second term at the age of 77, whereas Truman and Johnson were only 67 and 59 respectively when they announced their decision not to run again.
Second, the party establishment has tended to rally around candidates of their choosing over mavericks or insurgents who may be popular among the base. This is good news for Vice President Kamala Harris, the candidate who would almost certainly become the establishment favorite the moment Biden were to step back. While Harris’ ascendance would not be a foregone conclusion, she would certainly have a good level of party support and infrastructure to help launch her bid for the nomination.
But while she may be popular among Democratic activists, Harris could be a problem for the party in the general election. Her approval numbers are even lower than Biden’s, floating in the mid-to-high 30s. Moreover, she could face the same problems that the establishment candidates Stevenson and Humphrey did in 1952 and 1968: being seen as responsible for the incumbent president’s failures without benefitting from the advantages of incumbency itself.
Third, when a president decides not to run, their party typically has historically lost in the general election. If Biden were to step down, Democrats would likely be facing an uphill battle in the 2024 general. Again, two historical precedents don’t set a law in stone that retiring presidents’ parties always lose. But Democrats would be right to worry about what’s happened in the past and work to nominate the candidate who would be strongest in 2024 rather than the candidate who the establishment likes the most.
If Biden does choose not to run, Democrats should take this last point seriously. Rather than simply coalescing around Kamala Harris as Biden’s predetermined successor, Democratic voters should insist upon an open and competitive primary. And this time, unlike in 1952 and 1968, party leaders won’t be able to preempt the will of the party’s rank-and-file voters and simply anoint a candidate of their choosing. As we saw in 2016 when Bernie Sanders nearly took out Hillary Clinton, and again in 2020 when there were enough viable candidates to fill two debate stages, primaries today are competitive in a way that they were not earlier in the 20th century. And so in 2024, given the democratic nature of contemporary primaries, it’s completely feasible that a maverick or underdog could take the nomination even if the establishment rallies around Harris.
Over the past few years, the party has built out an impressive bench of politicians who may be fit for the job. To name just a few Democrats who might fit the bill, and in no particular order, there’s Michigan Governor Gretchen Whitmer, Georgia Senator Raphael Warnock, Transportation Secretary Pete Buttigieg, Massachusetts Senator Elizabeth Warren, California Governor Gavin Newsom, Vermont Senator Bernie Sanders, Pennsylvania Governor Josh Shapiro and many more who I won’t list, but who Wikipedia has helpfully and comprehensively listed.
Ultimately, however, all this hinges on Joe Biden. Until and unless he says otherwise, Biden will be the party’s nominee in 2024. Even so, the party should not want to be caught flat-footed should Biden decide that his time is up. For that reason, it’s important for Democrats to start thinking about what an incumbent-less 2024 would have in store. And there are worse places to start that process than by looking at the recent history of 1952 and 1968.