LAS VEGAS • Now it's on to Colorado, Minnesota and Maine.

With back-to-back victories fueling him, Republican presidential front-runner Mitt Romney is looking toward the next states that hold GOP nominating contests as main rival Newt Gingrich brushes aside any talk of abandoning his White House bid — all but ensuring the battle will stretch into the spring if not beyond.

Shortly after losing big to Romney in Nevada, the former House speaker emphatically renewed his vow to campaign into the party convention in Tampa this summer. His goal, he said, was to "find a series of victories which by the end of the Texas primary will leave us at parity" with Romney by early April.

Gingrich continued to shrug off Nevada's caucus results in an appearance Sunday on NBC's Meet the Press."

"This is the state he won last time, and he won it this time," he said of Romney. "Our goal is to get to Super Tuesday where we're in much more favorable territory."

But first, Gingrich must make it through Colorado and Minnesota, which hold caucuses Tuesday. Maine follows Saturday during a month that promises to be as plodding as January was rapid-fire in the presidential race. Romney will look to maintain his position of strength, if not build upon it, as his rivals continue working to derail him even as their options for doing so narrow with each victory he notches.

Former Pennsylvania Sen. Rick Santorum, who trailed the field in Nevada, insisted Sunday that "our numbers are moving up continually."

"I think we're going to show improvement. This race is a long, long way from being over," Santorum said on "Fox News Sunday."

And on ABC's "This Week," Texas Rep. Paul, who was in third Sunday night with 19 percent of the vote, maintained the results show voters are still up for grabs.

"I get energized because I know there's a large number of people who are looking for another option," Paul said.

With votes from 81 percent of the precinct caucuses tallied, Romney had 48 percent, Gingrich 22 percent and Santorum 11 percent. Turnout was down significantly from 2008, when Romney also won the state's GOP caucuses.

Romney's victory capped a week that began with his double-digit win in the Florida primary. That contest was as intense as Nevada's caucuses were sedate — so quiet that they produced little television advertising, no candidate debates and only a modest investment of time by the contenders.

A total of 28 Republican National Convention delegates were at stake in caucuses held across the sprawling state. Romney won at least 12, Gingrich and Paul at least four, and Santorum at least two. Six were still to be determined.

That gives Romney a total of 99, including endorsements from Republican National Committee members who will automatically attend the convention and can support any candidate they choose. Gingrich has 30, Santorum 16 and Paul seven. It will take 1,144 delegates to win the Republican nomination.

Preliminary results of a poll of Nevada Republicans entering their caucuses showed that nearly half said the most important consideration in their decision was a candidate's ability to defeat President Barack Obama this fall, a finding in line with other states.

About one-quarter of those surveyed said they were Mormon, roughly the same as in 2008, when Romney won with more than a majority of the vote in a multicandidate field.

on to Minnesota

Romney could face a significant challenge in Minnesota.

The mood has changed since the former Massachusetts governor won the state's caucuses in 2008. A state that once took pride in political consensus has turned as contentious as any other. Last summer's bitter government shutdown was a lowlight.

Romney campaigned four years ago as the more conservative choice than Arizona Sen. John McCain. This time around, Romney is the mainstream front-runner up against more conservative rivals in Gingrich and Santorum.

And that makes Tuesday's caucuses unpredictable. Chuck Slocum, who led Minnesota Republicans in the mid-1970s, says the activists expected to dominate a small turnout are among the most conservative in the country.

Meanwhile, Santorum, who has lost four straight contests, remains optimistic. He has been drawing standing-room-only crowds and promising his political fortunes will improve if he can make it to just one more state. On Sunday, he said the upcoming races in Minnesota, Missouri and Colorado could be chances for him to reset the race — a line he has used ahead of each of the last four races where he came up short.

fashioning an image

Gingrich is wooing NASCAR voters.

As he charts a possible course to the Republican nomination, aides say Gingrich will paint front-runner Mitt Romney as the candidate of the PGA golf tour while the former House speaker pursues the blue-collar mantle of Dale Earnhardt.

It's a strategy that exploits the class warfare Gingrich professes to oppose. Still, it could pay dividends once the GOP race again swings South. Gingrich sees delegate-rich Texas as a firewall in April. But he must slog through more than 30 contests before that.

"Our commitment is to seek to find a series of victories which would end at the Texas primary, which will leave us about at parity with Gov. Romney," Gingrich said at a news conference in Las Vegas.

It won't be easy. Coming off sizable wins in Florida and Nevada, Romney is again the undisputed front-runner in the Republican race, and before the 10-state battle on March 6 known as Super Tuesday, the Republican race will move through several more states seen as favorable to Romney, such as his old home state of Michigan.