Finally, after more than a year of often bitter internecine warfare, the battle for the 2024 Republican presidential nomination will be joined Monday night at more than 1,500 precinct caucuses across Iowa.

The results may tell us if the battle will be prolonged – or relatively brief. Already, half the participants in the GOP’s first debate last August are out of the race. Despite passing up all of the GOP debates – or because of it – former President Donald Trump remains the overwhelming front-runner.

Here is a look at what the four main candidates are offering Republican voters in Iowa – and the following week in New Hampshire.

Donald Trump: Trumpism, the pure version. Vows to resume the tumultuous presidency that voters rejected in 2020 – with a heavy dose of retribution against those he blames for ousting him or bringing legal charges against him.

“I am your warrior, I am your justice,” Trump said in a March speech in Waco, Texas. “For those who have been wronged and betrayed … I am your retribution.”

He has listed these targets: “The Biden crime family,” including President Biden; “deranged Jack Smith,” the special counsel investigating him, and others prosecuting him, such as New York Attorney General Letitia James; “the unelected bureaucrats and shadow forces who have weaponized our justice system”; “every radical district attorney and attorney general in America for their illegal, racist-in-reverse enforcement of the law”; “every known or suspected gang member in America and every one of them that is here illegally”; and others here illegally who will face “the largest domestic deportation operation in American history.”

Policy proposals: close the border on Day 1 and complete the Southwest border wall; expand oil and gas drilling (already at an all-time high); more personal and business tax cuts; try again to repeal and replace the Affordable Care Act; reclassify thousands of federal civil service workers so he can fire those who oppose his policies; end the war in Ukraine, presumably by stopping U.S. aid and accepting Russia’s terms.

Florida Gov. Ron DeSantis: Trumpism without the theatrics. Trump’s principal rival in GOP polls a year ago, DeSantis is fighting for survival in Iowa after failing to establish himself as the clear alternative. A second-place finish is a must.

He has mostly tempered criticism of Trump, decrying his failure to complete the wall and repeal the Affordable Care Act and his decision to lock down the nation at the start of the COVID pandemic. But DeSantis has refused to criticize Trump’s efforts to overturn the 2020 election results.

More recently, DeSantis has focused more on Trump’s character, though, like most rivals, DeSantis says he’ll back Trump if he’s the nominee.

Last week in an interview with NBC News and The Des Moines Register, DeSantis posed the GOP choice this way:

“Do we want the election to be about the issues that the American people are facing? Or do we want the election to be about Donald Trump’s conduct, about Jan. 6, about criminal cases and all this?’” He also questioned if Trump truly opposes abortions.

Policy proposals: DeSantis, who signed a Florida law banning abortions after six weeks of pregnancy, said he would sign a federal ban at 15 weeks. He would scrap the Internal Revenue Service, institute a “flat tax” eliminating all credits and deductions, and abolish the federal departments of Commerce, Education and Energy. He called the war in Ukraine “a territorial dispute,” rather than a Russian invasion.

Former South Carolina Gov. Nikki Haley: A kinder, gentler version of Trumpism. Campaigned less in Iowa, where religious conservatives dominate the GOP, than in New Hampshire, where thousands of independents will vote in the Republican primary, and she has the important backing of Gov. Chris Sununu. Polls show her challenging DeSantis for second in Iowa.

Like DeSantis, Haley criticizes Trump’s manner more than his policies. “Chaos follows him,” she told a CNN town hall last week. “And we can’t have a country in disarray and a world on fire and go through four more years of chaos.”

Policy proposals: Haley’s tone is more moderate than Trump’s and DeSantis’, though her positions are not too different on major domestic issues. She would sign a federal abortion ban but doubts one would pass. She criticized Trump for failing to curb federal spending. She once said she wouldn’t run if he did but changed her mind and, like DeSantis, would support him if nominated. She was forced on the defensive recently by failing until prompted to cite slavery as the cause of the Civil War and denigrating the importance of Iowa’s caucuses.

On foreign policy, she stands out by vowing to maintain the GOP’s traditionally muscular foreign policy, unlike Trump and many other Republicans. Highly critical of Russia, she favors continued U.S. aid to Ukraine, Taiwan and Israel.

Vivek Ramaswamy: Trump’s Mini-Me. An unknown entrepreneur at the outset who founded a pharmaceutical company, Ramaswamy has campaigned to Trump’s right but failed to rise from the single digits.

Policy proposals: He’d abolish the IRS, the Department of Commerce, the Nuclear Regulatory Commission and the Centers for Disease Control and Prevention, and raise the voting age to 25. He says, without evidence, that the Jan. 6 insurrection – in which Trump supporters attacked the Capitol – was “an inside job.”

Former New Jersey Gov. Chris Christie, the only major candidate attacking the former president head-on, announced Thursday that he is ending his presidential campaign.