LOVELAND, Colo. -- Ahead of Tuesday night's Colorado caucuses, Republican presidential hopefuls Mitt Romney and Rick Santorum, likely to finish one-two here, rallied supporters across the state.

"Colorado's got something to say about who our nominee is going to be, and I think I'm going to be that nominee," said Romney, speaking Tuesday morning at an RV dealership in Loveland.

Sticking to the same script as he did at rallies Monday in Grand Junction and Centennial, Romney again pointed his attacks directly at President Obama.

"He has failed -- he does not deserve a second term," Romney said "This has been the most anti-growth, anti-jobs, anti-investment administration I've seen since Jimmy Carter."

Romney, who won a sweeping victory in Colorado's 2008 GOP caucuses here, isn't mentioning his primary rivals by name on the stump -- but his campaign is stepping up its attacks through emails blasting Santorum and Newt Gingrich, who both campaigned in Colorado Monday.

Gingrich, who spoke to supporters Monday morning in Golden, was making his first and only campaign stop in Colorado, a state he seems to be ceding to Romney.

Santorum, following two full days of campaigning here last week, spoke Monday afternoon to a conference in Golden and then at a rally at DU Monday night, all in an effort to finish a strong second in Colorado.

Whereas Romney looked to discredit President Obama's effort to take credit for a recent drop in the nation's unemployment rate, Santorum looked to spin the news to discredit Romney.

"He's basically made the case that he's the CEO who can get the economy going," Santorum said about Romney in an interview with FOX31 Denver.

"The President of the United States is a bigger job than that. That's just one of the issues that confront this country. And while it may be the most important at the moment, we can't have a nominee whose chances depend on the unemployment rate staying high."

A Public Policy Polling survey released Monday night had Romney with 37 percent support, followed by Santorum at 27 percent and then Newt Gingrich at 21 percent.

"I can't imagine Romney not winning Colorado," former state GOP chairman Dick Wadhams told FOX31 Denver on Sunday. "But Santorum is campaigning hard here and has seen good crowds. Tuesday night, it'll be about the margin and how much Romney can win by."

Santorum, who campaigned Tuesday morning in Colorado Springs before heading to the second of four states he'll visit Tuesday, is hoping a strong showing here, coupled with a potential victory in Minnesota or Missouri, both of which also vote Tuesday, could breathe new life into his campaign and cast him as a more viable conservative alternative to Romney than Gingrich.

"I don't know if we're going to win here, but we're going to do a lot better than most folks expect," Santorum told FOX31 Denver.

Gingrich, desperate to regain the momentum he's failed to maintain following his win last month in South Carolina, cast Romney as a moderate who can't beat President Obama head to head.

"Gov. Romney doesn't represent profound change," Gingrich told a half-full hotel ballroom of supporters in Golden Monday morning.

"He's not a bad person, but he's also not a person who goes in with force and will and fundamentally changes things."We nominated a moderate in 1976 and we lost. We nominated a moderate in 1996 and we lost. We nominated a moderate in 2008 and we lost. The elite media would love to talk us into nominating another moderate."

Gingrich did not mention a series of new national polls that show President Obama with a significant lead over Romney in a hypothetical general election matchup.