But the debate comes a full 15 months before voters go to the polls in November 2024. And the Republican Party’s first official primary event — the Iowa caucuses — is five months away.

That may seem like a lot of runway until the actual vote, but early campaigning is not unusual in the US. In fact, the 2024 campaign season has gotten off to a somewhat slow start, with many Republican hopefuls hesitant to challenge former President Donald Trump, a conservative heavyweight with a strong following.

“This year has really taken a little while to gel,” said Robert Boatright, a professor of political science at Clark University in Massachusetts.

Nevertheless, Wednesday’s debate underscores the outsized significance of the pre-primary season, which can make or break electoral fortunes, according to Boatright.

“With a debate at this point in the game, candidates are not really campaigning for votes. They’re really campaigning to gain the perception that they’re a candidate of consequence,” Boatright said.

“It is important for the candidates to try to show to the media, to Republican donors and other elites that they have what it takes to be one of the last three or four candidates standing.”

Road to the election

The campaign season’s early start is, in many ways, a direct product of modern efforts to democratise the process of picking the nominees for major political parties.

In the past, party leaders selected their nominees far from public view. But the current system solidified in the early 1970s when the Democratic party — and the Republican party soon after — moved to make a series of state contests the deciding factor.

Under the system, candidates are allocated “delegates” based on their performance in state primaries and caucuses, events where voters can indicate their preference for a party’s nominee. The candidate with the most delegates at the end of the primaries is named the nominee at the party’s national convention, which kicks off the general election season.

The 1976 success of future President Jimmy Carter helped establish the modern emphasis on pre-primary campaigning. A peanut farmer and former governor from Georgia, Carter was a dark horse until he received an unexpected surge at the Iowa caucuses, after making numerous stops in the state.

Carter’s victory showed how even a low-profile candidate could gain momentum and transform the race through early campaigning, according to John Aldrich, a professor of political science at Duke University in North Carolina.

“Jimmy Carter figured out how to go from an unknown candidate to prominence by winning in the Iowa caucuses,” he told Al Jazeera. “It made him spring up as a serious contender, and everybody said, ‘Well, if Carter could do it, I can do that too.’”

But long-haul campaigns come with pressure to build up resources and support months before the first vote in the formal primaries.

The upcoming Republican debate, Aldrich added, is “essentially a quasi-Iowa contest — but not to win over the hearts and minds of voters”. Rather, he said, it is more about winning “the hearts and minds of people who are going to give you money, who are going to work for you”.

‘Invisible primary’

The pre-primary campaign period has come to be known as the “invisible primary”, which begins after candidates announce their run and before formal primary voting begins.

It is a time “where candidates are competing with each other for endorsements, for support from elites, for money and for standing in the polls”, Boatright said.

As a result, it is also a period when party officials and power donors hold an outsized influence over which candidates receive the resources to build the expansive infrastructure needed to mount an effective primary campaign.

After Carter’s victory, “both parties realised that, under this new system, outsiders could effectively come out of nowhere and win the nomination and that it was in their interest to try to prevent this from happening”, Boatright said.

He added it has become more common than not for candidates with influential party support before the primaries to win the eventual nomination.

Still, support from party officials and other establishment figures can only go so far, and there have been instances where “outsider” candidates have surged to popularity among primary voters.

That occurred during the 2016 election when Trump won primaries and caucuses in some of the states that vote earliest, including New Hampshire, South Carolina and Nevada. Those initial successes built the momentum that carried Trump through the rest of the primary races.

How does primary voting work?

Under the current system, all 50 states, as well as US territories, hold primaries or caucuses.

In states with primaries, votes are cast the same way they are in other elections.

Caucuses, meanwhile, involve small private gatherings — in churches, schools, libraries or private homes — where party members debate and eventually separate into groups based on the candidates they support. Delegates are then allocated to candidates based on how much support they received.

The current slate of primaries will begin on January 15, with Republicans voting in the Iowa caucus, and end on June 8, with Democrats holding a caucus in the Virgin Islands.

Because primaries are organised by state authorities and party officials, they vary across the country.

Some states hold open primaries in which any registered voter, regardless of party affiliation, can cast a ballot in one of the two major parties’ primaries.

Other states hold closed primaries, which limit participation in a party’s primary to registered members of that party.

Other states use a third approach: Voters unaffiliated with either party can choose which party’s primary they want to participate in.

Is the current set-up good for US democracy?

In many ways, the lengthy campaign season in the US is largely a product of the country’s clearly defined election cycle.

That can give candidates a lot of time to prepare, while giving the public “a lot of data” with which to make their decisions, according to Duke University’s Aldrich.

But the length “really does increase the need for major national organisational support, which does narrow that potential field” of candidates, he said.

The increased influence of “party elites” further removes citizens from the nomination process, Clark University’s Boatright added.

“In a lot of ways, the American system gives voters the illusion that things are more democratic than they are, that they’re playing more of a role than they actually are,” he said.