WASHINGTON

The race for the White House will officially begin Monday as the first-in-the-nation nominating contest takes place in Iowa following months of heated Republican campaigning.

The Iowa caucus has long signaled the start of the US primary season wherein parties select their presidential nominees in state-by-state contests ahead of November's nationwide election.

In the US, elections are largely left to the states to run so long as they are conducted in compliance with the US Constitution.

Most states use the primary system wherein voters take to polling locations across the territory to vote by ballot in what would be considered a more conventional form of election. Roughly one in five states use the caucus system.

It is a more antiquated form of voting in which caucusgoers gather in a room run by a political party and congregate in groups affiliated with a candidate. Those groups then give speeches in support of their candidate in an effort to draw support from other groups, as well as undecided voters who stand or sit together.

Delegates are then divided based upon the number of votes they ultimately receive at the end of the caucus. Unlike primaries, caucuses are run on election day by political parties, not states. States, however, set the dates on which caucuses and primaries are held.

Generally speaking, most people refer to caucuses and primaries collectively as primaries, or as the "primary season" in the US.

Democratic overhaul to primary calendar sparks fight with state authorities

In Iowa, just Republicans will caucus on Jan. 15. The national Democratic Party announced in February 2023 an overhaul of their primary calendar in a bid to give a larger voice to Black and minority voters.

Iowa and New Hampshire, traditionally the proud claimants to the first and second primaries in the nation, respectively, are overwhelmingly white states. In each, white Americans comprise some 90% of the population, according to the US Census Bureau.

The Democratic National Committee (DNC) chose to move its first primary to South Carolina, where the party’s calendar has the primary taking place Feb. 3. It is to be followed Feb. 6 with the Democratic primary in Nevada, where Latinos comprise some one-third of the population.

The calendar shift has led to a showdown with state authorities in New Hampshire. State law mandates that the primary be held seven days before other similar nominating contests. Since Iowa uses the caucus system, it does not apply.

Democratic leaders are now in a showdown with state officials in New Hampshire. Authorities there are insisting on holding the Democratic and Republican primaries together on Jan. 23.

New Hampshire Attorney General John Formella issued a cease-and-desist order Monday to the DNC’s Rules and Bylaws Committee after it told the state Democratic Party to “educate the public” that the Jan. 23 primary would be “meaningless.” It called the contest a “non-binding presidential preference event.”

Formella, in a letter to the committee, said the instruction runs afoul of state voter suppression laws.

The DNC has vowed not to award delegates at the national convention based on the results of the primary, and it is unclear how the row will be resolved as New Hampshire seeks to retain its key role as the first-in-the-nation primary.

Open vs. closed vs. hybrid nominating contests

Because states are constitutionally granted the authorities to run their elections, the manners in which they do so vary greatly. Primaries are no exception.

Primaries and caucuses can be held in either an open or closed model, or a mixture of the two.

In an open primary, an individual can vote for the candidate of their choice, regardless of their party registration. In all, 16 states hold such a contest, according to the National Conference of State Legislatures.

An additional eight states have primaries that are open to unaffiliated voters, allowing them to vote for any candidate they choose, regardless of party. While individuals registered with either main political party, many vote in their associated primary, however.

By contrast, a closed primary limits a voter’s choices to only a candidate associated with their political party. Independents and unaffiliated voters are barred from participation in the primary process. Just eight states have completely closed primaries.

Fifteen states use a partially open or partially closed system, with regulations varying greatly on a state-by-state basis.

A handful of other states use a form of “top-two” primaries in which a common ballot is issued and voters select their top two candidates.

Super Tuesday presents turning point in primary season

On March 5, primary contests will be held in 16 US states and territories representing a turning point in the election cycle. By the end of March, some 70% of all delegates will have been allocated.

That helps to explain why so many Republican presidential hopefuls, seeking to ensure their campaign remains viable, have been pushing hard in the 16 states.

While there will technically be four more months in the primary season, after Super Tuesday, the Republican field will become far clearer ahead of the nominating convention.

Candidates who fail to advance in national polling by the end of March are all but certain to end their struggling campaigns.

Biden, Trump likely nominees ahead of conventions

Former US President Donald Trump has long been considered the near-certain Republican nominee as he has held, for months, a commanding lead over the remaining Republican contenders. A compilation of national polling from the RealClearPolitics website has Trump leading all other candidates with 51% support among Republican voters.

US President Joe Biden, meanwhile, is largely running unopposed for the Democratic nomination, leaving him a wide-open path to securing his party’s nomination.

Whichever candidate garners the majority of their party's delegates will be considered the presumptive nominee heading into their national convention.

The Republican National Convention will be held over three days beginning July 15 in Milwaukee, Wisconsin. It will culminate with the official nomination of the party’s candidate, which barring a major shakeup in the ongoing field, will be Trump.

Democrats will gather the following month in Chicago for their national convention from Aug. 19-22. Biden is all but certain to officially become his party’s nominee during the event.

The conventions will mark the shift to the final phase of the presidential campaign where the Republican and Democratic nominees will lock horns more directly, including during a pair of pre-election debates currently scheduled for Sept. 16 in Texas, and Oct. 1 in Virginia.

Voters will take to polling stations across the country for Election Day on Nov. 5.