“When we cut taxes in 2017, I wrote The Tax Cuts and Jobs Act. Everybody said, 'Well guess what? Revenue will go down.' Well in 2018, after we wrote it in 2017, what happened? Revenue went up by 3%, and the next year, it went up by another 3%,” Scott said. “So what we know is that the Laffer Curve still works. That the lower the tax, the higher the revenue."

If you look at the sheer number of dollars collected, irrespective of inflation and without regard to the size of the overall economy or other factors, tax revenues went up very slightly.

Specifically, federal data shows that tax revenues rose between fiscal year 2017 and fiscal year 2018 by 0.4%. (Federal fiscal years run from Oct. 1 to Sept. 30.) The rise is smaller than almost every previous year since World War II, except for a handful of years in which tax revenues declined, largely due to recessions.
But even that increase isn’t really applicable because the fiscal year is different from the tax year.

And the Committee for a Responsible Federal Budget, a group that favors shrinking the federal deficit, found that the small increase in nominal dollars collected disappears once you add in other factors. If you adjust for inflation, the group found, tax revenues actually fell by 1.6%.
-Analysis by Aaron Sharockman, PolitiFact

Christie kicked off a discussion on keeping Social Security sustainable. He has proposed raising the retirement age for younger Americans as part of his reforms to the key welfare program, though wouldn't give a number when asked during the debate, saying that would be a negotiation with Congress.

"I'm not going to start negotiating until I get there," he said.

Haley has also said she would be open to raising the retirement age, though she also didn't give a specific number.

"What I can tell you is it's going to be those in their 20s just coming into the system, and it should reflect more of life expectancy. It doesn't do that now," she said.

Scott said as president he would "protect your Social Security" and would not be open to raising the retirement age.

DeSantis said the key to tackling Social Security is reducing inflation.

"I'm going to force Congress to stop spending so much money," he said.

He said he doesn't see how to raise the retirement age "when life expectancy is declining."

Ramaswamy said preserving Social Security would take "severe measures" to address national debt, including reducing the number of federal employees.

-ABC News' Meredith Deliso

Most of the candidates on stage said they want to increase the retirement age for Social Security benefits, with some like Christie and Haley mentioning that their proposals would mainly affect people like their children, who are in their 20s and 30s. Still, the idea of raising the eligibility age is extremely unpopular across the board. In March, 62% of Americans told Quinnipiac University they opposed raising the full retirement age from 67 to 70, with majorities opposing it in every age group. The GOP candidates are also in a tough spot because Trump has recently opposed raising the retirement age or reducing benefits. Additionally, coming off as anti-Social Security could also scare older voters, who tend to be more Republican and will make up a sizable chunk of the primary electorate.

-Analysis by Geoffrey Skelley of 538

NBC News moderator Lester Holt asked candidates how they'd alleviate high prices for Americans in the first days of their adminstration.

DeSantis said he'd give families breathing room by gutting President Joe Biden's economic strategy, which the White House calls "Bidenomics," stating that he'd "take all the executive orders the regulations, everything to do with 'Bidenomics,' I'm going to rip it up, throw it in the trash can on day one where it belongs."

Ramaswamy, too, slammed "Bidenomics" as a "lie" before pointing to his own business career as proof he can take on the job: "It will take a CEO in the White House with zero-base budgeting to get the job done."

Scott and Christie took a different approach, arguing energy independence is key to reducing prices.

Haley, asked specifically about rural Americans suffering under inflation, pitched cutting taxes on the middle class and reigning in federal spending.

-ABC News' Alexandra Hutzler