Candidates at a recent Republican presidential debate. (Jim Young/Reuters)

After Iowa helped trim the Republican field a bit, most of the remaining candidates -- save, apparently, Carly Fiorina -- will appear onstage Saturday night in an ABC News debate in New Hampshire, where they'll try to win over voters ahead of the state's Tuesday primary.

The top spots in New Hampshire are perhaps more up for grabs than in Iowa. According to the Real Clear Politics average of polls, Donald Trump is leading by some 16 points, but second and fourth place are separated by just four percentage points. It's a state many moderate, establishment candidates -- like former Florida governor Jeb Bush, New Jersey Gov. Chris Christie and Ohio Gov. John Kasich -- must perform in to keep their hopes alive.

Meanwhile, the rivalry between the top three -- Trump, Sen. Marco Rubio (R-Fla.) and Sen. Ted Cruz (R-Tex.) -- is as lively as ever.

In other words, expect plenty of personal and policy jousting among everyone onstage. Here are the top seven issues for the debate, which starts at 8 p.m.

1. Obama's mosque visit

President Obama greets students after his remarks at the Islamic Society of Baltimore on Wednesday. (Jonathan Ernst/Reuters)

President Obama visited a mosque in Baltimore on Wednesday, his first visit to one in the United States since taking office.

During his visit, Obama spoke about unity and religious tolerance, but the Republican field was split on whether his visit was a good thing. Trump appeared to question the president's Christian faith, wondering if maybe Obama "feels comfortable there." Rubio said the visit is yet another example of the president pitting Americans against each other. But Bush -- his brother, as president, having visited a mosque after the 9/11 terrorists attacks -- defended Obama's visit and asked what took him so long, but he also criticized the president's  handling of the Islamic State.

Public opinion may back up some of Republicans' criticism. A Pew Research Center poll shows the percentage of Republicans or Republican-leaning independents who think "most" or "half/some" of Muslims are "anti-American" has gone up 20 points between the time Bush and Obama stepped foot in a mosque. It's now 63 percent.

PF_2016-02-02_views-islam-politics-05

2. Rubio's accomplishments

"I guess it’s hard to say there are accomplishments."

That's a quote not from a Rubio opponent, but from a Rubio supporter.  When asked by MSNBC's "Morning Joe" hosts to name one of the Florida senator's accomplishments, former senator Rick Santorum (Pa.) — who dropped out of the GOP presidential race Wednesday and endorsed Rubio — stammered.

"Republicans have been in the majority for one year and one month -- of which, as you know, he was running for president primarily," Santorum said.

The sound bite was a gift from above for Rubio's challengers, and particularly for Cruz. After a strong showing in Iowa, Rubio is making the case he's the best chance Republicans have to win the White House in November. But Cruz, et. al., can point to the young freshman senator's limited record -- and, most damaging for Rubio, how it sounds a lot like another young, ambitious freshman senator who ran for president back in 2008.

Rubio, of course, could point out Cruz's own limited record in the Senate, which is mainly built on obstruction.

 3. Terrorism and the Islamic State

Given last fall's attacks in Paris and San Bernardino, Calif., terrorism and national security remain high on the 2016 topics list.

Polls show that a large majority of Americans are fearful of another terrorist attack and doubtful of Obama's ability to handle it, prompting the president to go on the offensive to highlight how much the United States is, well, on the offensive in Iraq and Syria to battle the Islamic State.

The national focus on terrorism ostensibly works in the Republican Party's favor. GOP candidates traditionally have earned more trust on national security issues from voters than Democrats have. But the most hawkish among the bunch, Sen. Lindsey O. Graham (S.C.), dropped out of the race in December and endorsed Bush. Graham said he wanted to put as many as 10,000 troops on the ground. No other candidate has gone that far — especially as Republicans recall the war weariness that marked the draw-downs in Iraq and Afghanistan.

So, though their tone will be different than Obama's — including on whether to call it "radical Islam" — their actual proposals have in many cases not differed in big and clear ways, either from Obama or from one another.

Plus, a Washington Post poll in November found Hillary Clinton is the most trusted 2016 candidate on terrorism.

4. The opioid epidemic

The debate's location, Manchester, N.H., is smack in the middle of one of the states struggling with a sudden spike in addictions to opioids -- heroin, yes, but also prescribed painkillers like Percocet. The once-underground, mostly lower-income scourge of opiate addiction has surged to the surface recently, crippling wealthy suburbs in states like New Hampshire. A poll conducted by ABC Manchester affiliate WMUR-TV in October, in fact, found New Hampshire residents ranked drug abuse as the No. 1 issue to them.

Presidential candidates on the right and left have taken note. Republicans in particular have found ways to share their own personal experiences with the addictions of family and friends.

Cruz shared his with The Washington Post's Katie Zezima on Friday.

Sen. Ted Cruz, his voice quiet, stood behind a podium and talked about the death of his sister, who struggled with addiction.

"Her son found her in bed. The coroner ruled it accidental. We'll never know. We just got the call one day that Miriam was gone," an emotional Cruz said after recounting his sister's life. She was a beautiful woman who let a young Cruz pull her hair, but Miriam was angry. She partied hard. She got into a car accident and became addicted to pain pills. She lived in a crack house. Cruz took out a $20,000 cash advance to send her son to military school.

"You know, as a family you wonder, could I have done more? Was there a way to pull her back? Was there a way to change the path she was on? Those are questions you never fully answer," Cruz said.

5. The economic recovery

In his final State of the Union address, Obama stressed how, under his watch, the United States was pulled back from the brink of a depression and is stronger for it.

"The United States of America, right now, has the strongest, most durable economy in the world," he said, ticking off record-setting private-sector job creation, the national unemployment rate being cut in half and the deficit being trimmed by almost three-quarters.

Republican candidates aren't nearly so quick to call that a win, especially when many voters still express skepticism that the economy is improving. To counter Obama's numbers, GOP candidates often point to the number of people who have decided not to look for work anymore. The labor force participation rate keeps dropping and now stands at 62.6 percent — down from more than 66 percent before the recession.

And a nonpartisan National Association of Counties analysis released reports that 93 percent of American counties have yet to fully recover from the recession, with about half recovering on one or fewer of four key indicators.


The darker the blue, the better a county's economic recovery. (Courtesy of the National Association of Counties)

On how they'd reboot the economy, GOP candidates have drawn more contrasts with Obama than with one another. Specifics are sparse, and the claims from governors — such as Kasich and Bush — of job growth in their states have come under scrutiny by fact-checkers. The Washington Post's Fact Checker team urges readers "to be wary about job-creation claims, either at the state or national level, as so much of what happens in an economy is beyond a politician’s control."

That probably won't stop those claims from being bandied about on Saturday, though.

6. Immigration

The perennial topic in the GOP primary race has mired several candidates in debate-night drama.

In an election year in which candidates such as Cruz and Trump have surged in part because of their hard-line stances on immigration, Rubio, Cruz and Bush are among those who have shifted their positions on immigration reform. (Cruz even came under fire from opponents and scrutiny from fact-checkers recently for his claim in a December debate that he never supported legalization for undocumented immigrants.)

But for all the barbs back and forth, there's little chance of immigration reform policy moving in Congress. In the wake of congressional inaction (the compromise Rubio helped craft that failed in the House in 2013), Obama has tried to go it alone by extending deportation relief to undocumented immigrants and some of their parents.

His executive actions are held up in courts because of a lawsuit led by Cruz's home state of Texas. But the stage is set for a Supreme Court decision on Obama's executive actions this summer — months before the president leaves office, and months before Americans will decide who replaces him.

7. Supporting the eventual nominee

Is Trump still the undisputed front-runner?

He came in second in Iowa -- and very nearly third. Plus, it's still an open question whether the nontraditional candidate has the campaign infrastructure to get New Hampshire voters out on a cold, potentially snowy night. Will those who have never voted in a primary before and say they like Trump show up for him?

Then there's the question of what support Trump would have if he were the nominee. By show of hands in the first GOP debate, the candidates all ostensibly pledged to support whoever would become the party's nominee — all except Trump. (Fox News Channel's Bret Baier asked the candidates to raise their hands if they would not pledge to support the nominee and would not rule out a run as an independent. Trump was the only one with his hand raised, and either he or the question — or maybe both — were booed by the audience.)

But in the wake of Trump's suggestion to temporarily ban Muslims from the country, that has become a pledge many candidates appear to wish they could walk back — especially as it looks increasingly possible that Trump could win the Republican nomination.

From Bush to Fiorina, candidates have sidestepped questions about whether they'd support Trump if he were the nominee.

Unfortunately for them, the scenario they're trying to avoid commenting on is still quite possible.

Correction: An earlier version of this story had an incorrect time for the start of the debate.