Why the 2024 US presidential election will likely be a choice between Biden and Trump again

Why, in a country of more than 330 million people, does it appear that Americans will have to choose between Joe Biden or Donald Trump at the 2024 US presidential election?

Sure, not everyone can run for president. Anyone under the age of 35 is out, as are those born overseas and non-residents of 14 years or more. It helps to be well-known, popular and to sit on an eye-watering pile of money; the 2020 presidential election cycle, for example, cost candidates a combined US$5.7 billion ($A8.37 billion), more than the GDP of several small countries.

Read more: Politics with Michelle Grattan: Author Bruce Wolpe on the "shocking" consequences for Australia of a Trump 24 win

Those who have previously served in an official role also have advantages when it comes to competing for the top job. Having a known political track record, public name recognition, and existing voter support all go a long way to financing campaigns and encouraging voter turnout.

But even with all that considered, the pool of possibles surely could not be reduced to the same two candidates as 2020. So, why then are the odds of Biden and Trump going head-to-head once again so good?

Why Biden?

The fate of the Democrat nomination process is almost certainly sealed, with President Joe Biden as the Democrats’ nominee for the 2024 election. There are two main reasons for this.

Firstly, any primary challenge from a serious Democrat contender would present undue risk to the “incumbent advantage” of the party. With only ten of the 45 former presidents unable to secure second terms, incumbent presidents generally have a pretty good shot at winning a second term in office.

The punishing reminder of Senator Ted Kennedy’s fierce and unsuccessful primary challenge to incumbent President Jimmy Carter in 1980 is no doubt curbing any Democrat’s bid to take on Biden. Combined with Carter’s low approval rating and a country bogged down in “malaise”, the challenge all but paved the way for Ronald Reagan’s walloping victory with 489 Electoral College votes to Carter’s 49.

A president, like Carter, seeming to grovel for their own party’s support after a leadership contest, is an easy target for the opposition. A Democrat party united in full faith behind the incumbent leader – Biden – has a better chance of beating the Republican nominee.

Secondly, even if a serious Democrat could shake off the cautionary tale of 1980, there is no clear persuasively electable alternative to Biden. More than half of American voters do not want Biden to run in 2024, but dissatisfaction with a sitting president isn’t new. For example, 60% of Americans did not want Reagan to run again in 1984, despite him having a relatively high approval rating at the time.

It is one thing to not want the president to run again and yet another to unanimously agree on the alternative. No prominent Democrat officeholders appear willing or have enough support from the party or the public to suggest a challenge would be successful.

Kamala Harris, as Vice President, probably has the next best chance to secure the Democratic nomination. Every sitting or former vice president who has sought Democrat leadership since 1972, including Biden, has been successful. However, Harris suffers even lower approval ratings than Biden, and her chances at winning election in November are less predictable.

The reality is, despite being 80 and sometimes appearing frail, Biden is an electable leader. He won the popular vote in 2020 by more than 7 million votes and a 4.5% victory margin. And among his own party the president maintains a high approval rating, with 82% of Democrats approving of Biden in June 2023.

For Democrats who might dislike Biden, the only thing worse than a second Biden term, is a second Trump term; while they might not like it, Biden presents the best chance at re-election next year.

Why Trump?

The story is a little different when it comes to the Republican party nomination. Trump is not as likely as Biden to secure the nomination for his party in 2024. Still, the former president remains the clear front runner ahead of the main primary season, averaging 50% of the party’s support as the preferred nominee, and maintaining a 32-point lead over his nearest rival, Florida Governor Ron DeSantis.

Trump’s campaign to reclaim office is the first attempt of any former president to regain office after losing in over 130 years. Unlike other one-term modern presidents who might have sought a second term after losing, Trump seems to have fewer issues persuading Republican voters and the party that he could be a winner once again.

Not only did Trump only lose the Electoral College by a razor thin count (the equivalent of around 44,000 votes), but an average of two-thirds of Republican voters believe Biden’s victory was fraudulent. An unforgettable 147 House Republicans also voted to reject Biden’s 2020 victory in January 2021, believing it was stolen from Trump.

Read more: You might think Trump being found liable for sexual abuse and defamation would derail his re-election campaign. But it's not that simple

Almost all the Republican primary challengers are reluctant to openly criticise the former president. They have stood him even amid the two recent criminal indictments, which would ordinarily present a golden opportunity for opponents to give their own campaigns an edge. For so-called “Teflon Don”, the scandals have done little to dissuade and unstick the Trump-loyal Republican base, and have only served to starve Trump’s opponents of media oxygen.

Of course, Trump’s nomination far from a home run, and the primary process is often long and unpredictable. But like the Democrats, the major question facing the party is, if not him, then who? And the party is coming up short with a more compelling answer.

The crowded Republican field and winner-takes-all nature of the system means it is very difficult for non-Trump-supporting Republicans to coalesce around a single alternative with a margin big enough to surpass Trump’s lead. Even DeSantis, who was once crowned “DeFuture” of the party and is supposedly the best chance of taking on Trump for the nomination, has found his popularity and momentum waning in recent weeks.

Ultimately, it is still too hard to know for sure what the election in November 2024 will look like, and any US political watcher will be loath to make any firm predictions after surprises in both the 2016 and 2020 presidential elections.

But, at this point in the election cycle, despite the wants of the majority of Americans, and no matter how uninspiring – 2024 looks to be 2020 all over again.