MANCHESTER, N.H. (AP) -- An aggrieved Donald Trump was rejoining his Republican presidential rivals on the debate stage and hoping for a winning formula in New Hampshire, while the challenge for surging Marco Rubio was fending off attacks from other candidates.
The debate Saturday night comes three days before New Hampshire's first-in-the-nation primary, a contest that will likely determine whether some contenders in an already shrinking field will move on or abandon their White House hopes.
Trump, a billionaire who is largely paying for his campaign, has enough money to stay in the race, but anything short of a first-place finish in New Hampshire would damage his White House bid. He has held a comfortable lead in national polls, as well as surveys in Iowa and New Hampshire for months, but had to settle for second in last Monday's opening caucuses.
"I think we should have come in first, to be honest with you, a lot of things happened there. A lot of things happened," Trump said Friday during a rally in South Carolina. The real estate mogul skipped the final debate before the Iowa caucuses, but has committed to more traditional campaign activities in the days before the New Hampshire's vote.
Chris Christie told a campaign rally in Bedford on Saturday that Trump would be welcomed back to the stage "with open arms," and the New Jersey governor was thrilled that "none of you people made enough fun of Donald Trump to make him not come tonight."
Rubio's third-place finish in Iowa gave him the edge among those candidates viewed as more mainstream alternatives to Trump and Texas Sen. Ted Cruz, the fiery conservative who won Iowa. As a result, the Florida senator has faced a flurry of criticism in recent days, with his rivals questioning his experience and casting him as overly scripted.
"He's a great guy, but he's not a leader," said former Florida Gov. Jeb Bush. New Jersey Gov. Chris Christie has repeatedly derided Rubio as a "bubble boy" whose staff protects him from having to answer tough questions about his record and what he would do as president.
Bush, Christie and Ohio Gov. John Kasich have largely staked their presidential hopes on New Hampshire. Those falling short of a standout finish in New Hampshire will face party pressure to quit.
Also fighting to stay relevant is retired neurosurgeon Ben Carson. After a disappointing showing in Iowa, he took time off from campaigning. He hasn't been a major presence in New Hampshire.
Cruz carried Iowa with the support of the evangelical voters who hold significant sway in the state. In New Hampshire, he was making an appeal for support from libertarian voters.
The Iowa caucuses helped trim the GOP field, allowing debate host ABC News to scrap an undercard event for low-polling candidates. The debate rules left Carly Fiorina as the only candidate without a spot on stage.
Fiorina has protested her exclusion, and Republicans such as 2012 presidential nominee Mitt Romney have come to her defense.