The debate on Wednesday will offer the candidates a chance to directly make their case to the American public as they seek to narrow the gap with former President Donald Trump, who remains far ahead of the pack.

With Trump – who has not confirmed whether he will attend the debate – beset by legal issues, the event provides an opportunity for Florida Governor Ron DeSantis, former Vice President Mike Pence and the other candidates to present themselves as viable alternatives.

The debate comes nearly six months before the Republican primary season – a series of state-level contests in which party voters choose their presidential candidate – kicks off in Iowa.

The list of debate participants has not been finalised, but US media outlets have reported that eight candidates have qualified so far. Republican rules state that a candidate must have at least 1 percent support and 40,000 individual donations to qualify, and they must also sign a pledge to support the eventual Republican nominee in the general elections.

Here, Al Jazeera looks at the key issues that could shape the first debate of the 2024 vote:

Will the other candidates target Trump?

In a field with multiple candidates, frontrunners normally take a lot of shots from rivals looking to chip away at their lead, but Trump has largely been spared direct attacks from most of his opponents.

Chris Christie, a one-time ally of the former president, has made rebuking Trump a defining element of his candidacy, but the ex-New Jersey governor is mounting a long-shot campaign at best with his support among primary voters lingering at around 3 percent.

DeSantis, Trump’s closest opponent, has been reluctant to go all out against the former president. Instead, the governor has criticised Trump on specific policy issues, sometimes without naming him.

Some of the other candidates also have avoided taking a clear position on Trump’s mounting legal woes.

For his part, Trump has not shied away from denouncing his Republican challengers, often taking to social media to hurl insults at them and remind them of their past support for him.

Whether Trump makes it to the debate stage, one of the chief takeaways of the evening will be how the other candidates will deal with him.

Ukraine support

Foreign policy has been a major source of division among Republicans.

The party is home to both hardline isolationists and staunch interventionists and that chasm has been on full display in recent months when it comes to US support for Ukraine.

While candidates such as Trump and DeSantis have voiced scepticism about Washington’s assistance to Kyiv, Christie and Pence have argued that the US should do more to help Ukraine.

Trump has refused to commit to continuing the aid if re-elected, and DeSantis has called the conflict a “territorial dispute”, but Christie and Pence recently visited Kyiv and met with Ukrainian President Volodymyr Zelenskyy to show their support.

The US has provided Ukraine with tens of billions of dollars in military, humanitarian and budgetary assistance since the Russian invasion began in 2022, leading some Republicans to argue that the funds are better spent at home.

Republican voters are also divided on the issue: A Gallup survey in June showed that 50 percent of Republican respondents said the US is doing too much to support Ukraine.

The debate will provide a chance for the candidates to articulate and argue their positions on Ukraine, a consequential topic over which the US president has considerable influence.

Abortion

Since the US Supreme Court overturned the constitutional right to abortion last year, the issue has been a political Achilles heel for Republicans. Public opinion polls and election contests have shown that most Americans oppose further restrictions on reproductive rights.

Still, the Republican base continues to largely identify as opponents of abortion, which means the party’s candidates will face a challenging task of appealing to those supporters during the primaries without alienating the wider US electorate in 2024.

Trump appointed three of the five conservative Supreme Court justices who overturned Roe v Wade, the precedent that established abortion rights, in June 2022. But the former president has not confirmed whether he would back a federal ban on the procedure.

DeSantis has signed one of the strictest abortion laws in the country, banning abortions in Florida after six weeks of pregnancy, while Pence has been courting Christian religious voters who oppose abortion.

But differing approaches are emerging among the candidates with Trump suggesting Florida’s restrictions are “too harsh”.

At the debate, the candidates will likely have to make their position known on the issue, including whether they would support restrictions at the national level.

Culture war issues

Social issues, over which the president has limited powers, have become a major feature of electoral politics in the US.

In fact, DeSantis rose to national prominence by championing right-wing social causes in Florida and rejecting what he calls “woke” policies focused on identity and social justice.

Trump recently said he does not like the term “woke”, which has become a rallying cry for conservatives against what they see as a disproportionate liberal focus on race, historical injustices, gender identity and sexuality.

Still, the former president, who launched his 2016 campaign by calling undocumented Mexican immigrants “rapists”, has been regularly accused of bigotry himself.

The first debate may set the tone for how much the candidates will focus on so-called “culture war” issues versus other policy topics.

Support for Israel

With evangelical Christians, who back Israel for theological reasons, growing into a decisive segment of the Republican base, staunch support for Israel has become a constant feature of Republican primaries.

And the upcoming debate will have no shortage of stalwart Israel supporters.

Former US Ambassador to the United Nations Nikki Haley’s diplomatic career was mostly defined by her defence of Israel at international forums.

DeSantis has prided himself on penalising companies in Florida that boycott Israel and falsely stated that the Palestinian West Bank is not occupied territory.

While in office, Trump was often described by Israeli Prime Minister Benjamin Netanyahu as the best friend Israel has ever had in the White House.

Trump moved the US embassy to Jerusalem, recognised Israel’s claims to the occupied Syrian Golan Heights, and brokered diplomatic agreements between Israel and Arab states.

US President Joe Biden has largely maintained Trump’s pro-Israel line – and in some instances, moved US policy even further in favour of the country – but Republican candidates will likely try to outdo him with pro-Israel statements at the debate if the subject comes up.

Presidential campaigns have previously produced anti-Palestinian comments and policy proposals.

For example, ahead of the 2012 elections, then-Republican candidate Newt Gingrich called Palestinians an “invented” people, and three years later, Ben Carson, who went on to serve in Trump’s cabinet, said a Palestinian state should not be established on “Israeli territory”.

“Is that necessary, or can you sort of slip that area down into Egypt?” Carson said at the time.