Washington — Florida Gov. Ron DeSantis, once widely viewed as the favorite to challenge former President Donald Trump for the GOP nomination, but now who appears to be battling Nikki Haley for second place, said his campaign feels "really good" heading into Monday night's Iowa caucuses. 

After months of betting big on the Hawkeye State, DeSantis is nodding to the returns he hopes to see on the investment, even as polls show Trump maintaining a dominant lead.

• What is a caucus and how does it work? What to know about Iowa voting

"When people take a poll, they can push someone one way or other, but there's a lot of people that still haven't made up a final decision," DeSantis told "CBS Mornings" anchor Tony Dokoupil. "So I think we're in good situation to be able to capture that."

DeSantis has struggled to narrow the gap with the former president since launching his White House bid in May, despite an impressive initial fundraising haul. Still, he's invested heavily in Iowa and has traveled to all of the state's 99 counties, earning the endorsement of Iowa Gov. Kim Reynolds in the process. 

DeSantis said his team has found as they go door to door that Iowans are still weighing their options — between the former president and the Florida governor. 

"That's kind of where they're at right now," DeSantis said. "So we definitely have an ability to pick up, but what we've been able to do up to this point, I think, is going to pay dividends and I think people are going to be surprised."

DeSantis drew a clear line between himself and the former president, saying that while Trump has focused on "his issues," the Florida governor is focused on the country.

"It's not about me. It's about the future of the country," DeSantis said. "I've delivered on 100% of my promises. You know, Donald Trump did not build the wall, did not drain the swamp."

But it's not only the former president who now poses a challenge to DeSantis. Expected to add to that dynamic is new momentum seen in recent months around Haley, which has thrown DeSantis' expected runner-up status into question. 

With the stakes high in Iowa for DeSantis, coming up third — or with a paltry second-place performance —could doom his presidential prospects just as the nominating content gets underway.

In:
• Iowa Caucuses
• Ron DeSantis

Kaia Hubbard

Kaia Hubbard is a politics reporter for CBS News Digital based in Washington, D.C.