Tensions between Ben Carson and Donald Trump will be on full display Wednesday night at the third GOP presidential debate where issues like the economy, jobs and taxes will be the center of attention.
At 8 p.m. ET, the top tier of Republican candidates will face off on CNBC. They are Trump, Carson, Jeb Bush, Chris Christie, John Kasich, Carly Fiorina, Ted Cruz, Rand Paul, Marco Rubio, and Mike Huckabee.
CNBC says the moderators -- Carl Quintanilla, Becky Quick and John Harwood -- are planning to ask contenders about Americans' financial freedom, the health of the economy as well as jobs, taxes and the deficit.
The second tier of the candidates will participate in a "happy hour" debate at 6 p.m. ET. They are Lindsey Graham, Bobby Jindal, Rick Santorum and George Pataki.
The debate, held at the University of Colorado Boulder, comes on the heels of national and battleground state polls showing Carson taking the lead from Trump. A CBS News/New York Times survey released Tuesday found 26 percent of primary voters nationwide said they back Carson while 22 percent said they support Trump. It marks the first time Trump has fallen out of the lead since he first launched his campaign in June.
"Will you get the numbers up, Iowa, please? This is ridiculous," Trump said about his deteriorating support at an event in Sioux City, Iowa on Tuesday night. "Second is terrible for me."
Multiple polls from the last week found that Carson, a retired neurosurgeon, took the lead in Iowa, even opening up a 14-percentage-point lead over Trump in one survey.
While the two frontrunners will be under the spotlight, their competitors will be trying to steal it from them.
Kasich, the governor of Ohio, has been much more aggressive on the campaign trail recently.
"I've about had it with these people," he yelled at a pre-debate rally on Tuesday. "What has happened to our party? What has happened to the conservative movement?"
Kasich could benefit from Wednesday's debate. He served as chairman of the House Budget Committee from 1995 until 2001 and he argues he helped balance the federal budget while in Congress.
Bush, meanwhile, will be seeking to stand out as his campaign undergoes a restructuring amid weak poll numbers. Late last week, the campaign said it would be cutting payroll costs by 40 percent, eliminating positions and slashing salaries.
And the debate comes the same day the House is set to vote on a budget deal that would lift spending levels by $80 billion over two years and raise the debt limit through mid-March 2017.
Three contenders in the Senate -- Rubio, Cruz and Paul -- have already come out against the deal.
Paul has already pledged to filibuster the agreement in the Senate to try to delay it from advancing. On Tuesday, he described the deal as "horrible" and said "it's hard for me not to use profanity" when talking about it.
Carson, meanwhile, has struggled with questions regarding the debt ceiling and federal budget. In a series of interviews since early October with various news outlets, Carson has not made his position on the debt ceiling clear. In fact, in at least one interview, he appeared to confuse the nation's borrowing authority with increasing government spending.
As for Fiorina, she could have a strong night if she performs as well as she did in the second debate last month. The former CEO of Hewlett Packard's approval numbers shot up in surveys after her performance, but they've fallen significantly since then.
During the debate, Hillary Clinton's campaign will begin airing ads highlighting the fights for college affordability, equal pay and higher incomes in Iowa and New Hampshire.
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