Ramaswamy introduced himself to a national audience from center stage, arguing that an outsider is needed to move America forward.

"First, let me just address a question that is on everybody's mind at home tonight: Who the heck is this skinny guy with a funny last name and what the heck is he doing in the middle of this debate stage? I'll tell you, I'm not a politician. Bret, you're right about that. I'm an entrepreneur," Ramaswamy told co-moderator Bret Baier.

"Now is our moment to start running to something to our vision of what it means to be an American today. If you have a broken car, you don't turn over the keys to the people who broke it again. You hand it over to a new generation to actually fix the problem. That's why I'm in this race, and we're just getting warmed up."

In his response on how to steady the economy, Christie pointed to his record taking on debt in New Jersey and argued he could do the same in to "fight waste" in Washington -- invoking a cut-the-spending mentality that has long been popular among conservatives but became less prominent with Trump's rise, as he focused on other initiatives.

"We cannot sit by any longer and allow the kind of spending that is going on in Washington," Christie said. "Every dollar they spend is a dollar that these people are not allowed to spend on their children and grandchildren. It is robbing our country and it is wrong."

Scott also jumped on government spending as a major problem, touting his votes against legislation by Democrats.

"Over the last several years, I've had an opportunity to vote against spending package after spending package after spending package," Scott said. "And we also need to understand is that Joe Biden's Bidenomics has led to the loss of $10,000 of spending power for the average family."

Interesting early questions by the Fox News hosts. DeSantis got to go first, understandably, and he didn't face any questions about his tenure as governor. By comparison, when the hosts turned to Christie and Scott, they faced questions about state debate in Christie's case and Scott's voting record on spending bills. Both seemed caught a little off balance by actual scrutiny of their records.
-Analysis by Geoffrey Skelley of FiveThirtyEight

Interesting early questions by the Fox News hosts. DeSantis got to go first, understandably, and he didn't face any questions about his tenure as governor. By comparison, when the hosts turned to Christie and Scott, they faced questions about state debate in Christie's case and Scott's voting record on spending bills. Both seemed caught a little off balance by actual scrutiny of their records.

Trump maintains a lead of 25 percentage points over his nearest competitor in Iowa, according to the latest polls.

DeSantis and Scott are both polling higher in Iowa than they are nationally, according to our polling average. Trump is polling about 10 points lower in Iowa than in national polls.

According to a July poll from J.L. Partners/DailyMail.com, only 51 percent of Iowa Republicans said their mind was made up. Forty-three percent said they could still be persuaded to support another candidate. Voters who said they plan to vote for Trump were the most likely to say their mind is made up, with 80 percent saying so compared with 37 percent of those who said they plan to vote for DeSantis and 11 percent of those who said they plan to vote for Scott.

Scott and DeSantis have the highest net favorability among Iowa Republican voters. Pence, Christie and Hutchinson are underwater.

In an early state poll from the Manhattan Institute conducted in July, Iowa Republicans are split on whether electability is important. Forty-six percent of Iowa Republican voters say that it is most important for Republican candidates to win elections and be in power, even if that means compromising or moderating their positions, while 45 percent said it is most important for candidates to stay true to their principles, even if that means losing elections.

Iowa Republicans also think that skipping primary debates shows weakness more than strength, according to a July Fox Business/Beacon Research/Shaw & Co. Research survey. Fifty-nine percent of Republicans said skipping the debate shows weakness, while 27 percent said it shows strength.

-Analysis by FiveThirtyEight