Saturday night's Republican debate will be the last chance New Hampshire voters have to see the candidates together ahead of next week's first-in-the-nation primary.

Party front-runner Donald Trump won't sit out this time around, as he did ahead of the Feb. 2 Iowa caucuses when he scheduled a rally to coincide with Fox News' debate.

Despite his 11-point lead over Florida Sen. Marco Rubio in a new CNN/WMUR poll, voters were still trying to decide whether Trump is electable. Just 18 percent of undecided voters said they are leaning toward Trump, while 37 percent said they wouldn't vote for him at all.

Rubio, who gained momentum with a third-place finish in Iowa, is polling second in New Hampshire, ahead of GOP caucus winner Texas Sen. Ted Cruz.

Who's in, Who's out

Aside from extending invitations to Trump, Rubio, and Cruz, ABC News announced the following candidates would participate: former Florida Gov. Jeb Bush, retired neurosurgeon Ben Carson, New Jersey Gov. Chris Christie, and Ohio Gov. John Kasich.

Candidates received an invitation if they either placed in the top three in Iowa, averaged among the top six in national polls, or placed in the top six in New Hampshire polls.

Unlike the Jan. 28 GOP debate, this one won't have an undercard. Former Virginia Gov. Jim Gilmore and former Hewlett-Packard CEO Carly Fiorina didn't make the cut, leaving them without a national audience days ahead of the pivotal primary.

Fiorina and Gilmore participated in the previous undercard alongside former Arkansas Gov. Mike Huckabee and former Pennsylvania Sen. Rick Santorum, who both dropped out following a poor showing in Iowa.

Several prominent Republicans, including 2012 GOP presidential nominee Mitt Romney, lobbied for Fiorina's inclusion. Fiorina sent a letter to the Republican National Committee on Wednesday making her case, saying, "Our debate process is broken."

"Networks are making up these debate rules as they go along -- not to be able to fit candidates on the stage -- but arbitrarily to decide which candidates make for the best TV in their opinion," Fiorina wrote. "It is time for the RNC to act in the best interest of the Party that it represents."

Rubio Gains Steam, Trump Loses it

Rubio was polling at 18 percent in New Hampshire in large part to his strong showing in the Hawkeye State, prompting Christie and Bush to spend last week discrediting Rubio's political record.

Christie launched an all-out personal attack on the Florida senator, calling him "a boy in the bubble" and likening him to the king of England. Bush questioned Rubio's accomplishments while in office, going so far as to take out a full-page ad in the New Hampshire Union Leader.

"While Senator Rubio is a tremendous political talent, he is not the best choice to serve as Commander-in-Chief," the message read. "Nearly every political leader in Florida of stature who knows Marco and Jeb's records have joined us in endorsing Governor Bush."

Trump, for his part, said he believed skipping the debate in Iowa may have cost him votes during the primary.

"That could've been with the debate," Trump told reporters in Milford, New Hampshire on Tuesday. "I think some people were disappointed that I didn't go into the debate."

Trump's 66 percent favorability rating ahead of the Iowa caucus fell by five percent soon after, though he is still favored to come out the winner in the coming contest.

Online Viewing

ABC News is live streaming the debate beginning at 8 p.m. ET. The network will stream the event on ABCNews.go.com and through their ABC News mobile app.