Republican presidential candidates are introduced during the CNN presidential debate in Las Vegas, Dec. 15, 2015. From left are Ohio Gov. John Kasich, Carly Fiorina, Sen. Marco Rubio of Florida, Ben Carson, Donald Trump, Sen. Ted Cruz of Texas, Jeb Bush, New Jersey Gov. Chris Christie and Sen. Rand Paul of Kentucky. Ethan Miller/Getty Images

With seven weeks until the Feb. 1 Iowa caucus and most polls showing Donald Trump as the front-runner, CNN will have the billionaire businessman at the center of the stage at Tuesday night's Republican presidential debate. But a poll released over the weekend by the Des Moines Register/Bloomberg Politics has Texas Sen. Ted Cruz in first place in Iowa. Trump called the poll "biased."

The CNN debate is the fifth one so far and the last debate in 2015 for the Republican presidential hopefuls. Trump and Cruz will be onstage primetime along with retired neurosurgeon Ben Carson, Florida Sen. Marco Rubio, former Florida Gov. Jeb Bush, businesswoman Carly Fiorina, New Jersey Gov. Chris Christie, Ohio Gov. John Kasich and Kentucky Sen. Rand Paul.

Ahead of the debate in Las Vegas, here’s a look at where the remaining candidates stand in various polls (that are not unanimous in their rankings).

Donald Trump

Republican U.S. presidential candidate Donald Trump addresses a crowd during a presidential forum in Aiken, South Carolina, Dec. 12, 2015. Reuters/Christopher Aluka Berry

Topping the crowded field (or tied with Ben Carson) for a few months, Trump still holds the lead, according to an NBC/Wall Street Journal poll released Sunday, showing the real estate mogul with 27 percent support from Republican primary voters. In a Monmouth University poll released Monday, Trump also leads the pack with 41 percent support. However, a Fox News poll released Sunday had Trump in second place with 26 percent compared to Cruz’s 28 percent, highlighting the Texas senator’s recent surge. Trump has come under fire over the past week for proposing that Muslims be banned from entering the U.S.

Sen. Ted Cruz

Ted Cruz
Republican presidential candidate Sen. Ted Cruz arrives to speak at the Heritage Foundation Dec. 10, 2015, in Washington, D.C. Alex Wong/Getty Images

Depending on which poll you decide to prioritize, the Texas senator could be in first place. A Des Moines Register/Bloomberg Politics poll released Saturday had Cruz in first place in Iowa at 31 percent, compared to Trump’s 21 percent. The NBC/Wall Street Journal poll has Cruz in second place with 22 percent.

Sen. Marco Rubio

Marco Rubio
U.S. Republican presidential candidate Sen. Marco Rubio speaks at a Defend and Reform Veterans and Military Town Hall at Noah's Event Venue in West Des Moines, Iowa, Dec. 10, 2015. Reuters/Scott Morgan

The Florida senator is coming in third place, with the NBC/Wall Street Journal poll showing Rubio with 15 percent while the Fox poll has him at 13 percent.

Ben Carson

Ben Carson
U.S. Republican presidential candidate Ben Carson speaks during a news conference in Chicago, Dec. 10, 2015. Reuters/Jim Young

The former neurosurgeon has dropped in the polls in recent months after polling near the top in September and October. The NBC/Wall Street Journal poll has Carson in fourth place with 11 percent and the Fox poll also has him in fourth place with 10 percent.

Former Florida Gov. Jeb Bush

U.S. Republican presidential candidate Jeb Bush waits to speak at the Devine Millimet FITN Candidate Series Forum in Manchester, New Hampshire, Dec. 8, 2015. Reuters/Brian Snyder

Bush has failed to break into the top of the pack with the NBC/Wall Street Journal poll ranking him in fifth place with 7 percent while the Fox poll has him tied for fifth place with Kentucky Sen. Rand Paul.

Carly Fiorina

Carly Fiorina
Republican presidential candidate Carly Fiorina speaks at a Republican Jewish Coalition forum at the Reagan Building and International Trade Center in Washington, D.C. Dec. 3, 2015. Reuters/James Lawler Duggan

The former Hewlett-Packard chief executive has also failed to gain ground recently, with the NBC/Wall Street Journal poll showing Fiorina in sixth place with 5 percent. The Fox poll has Fiorina coming in with only 2 percent support.

New Jersey Gov. Chris Christie, Ohio Gov. John Kasich, former Arkansas Gov. Mike Huckabee, former Pennsylvania Sen. Rick Santorum, South Carolina Sen. Lindsey Graham, former New York Gov. George Pataki and Paul all failed to earn more than 3 percent in the NBC/Wall Street Journal poll.