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 here, 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 on 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 both hold caucuses Tuesday. Maine follows on 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.

The former Massachusetts governor held a double-digit lead Sunday morning over his nearest pursuer as the totals mounted in Nevada, where fellow Mormons accounted for roughly a quarter of all caucus-goers. Gingrich and Texas Rep. Ron Paul vied for a distant second. Former Pennsylvania Sen. Rick Santorum trailed the field.

Santorum won the leadoff caucuses in Iowa and has trailed in the contests since then. He nonetheless insisted on 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," Paul 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 87 percent of Nevada's precinct caucuses tallied, Romney had 48 percent, Gingrich 22 percent, Paul 19 percent and Santorum 11 percent.

Votes were still being tallied in Clark County, the state's most populous and home to the Las Vegas Strip, where officials stayed up until the wee hours of Sunday morning counting ballots, but still couldn't finish the task. The fate of the state GOP's 28 delegates remained unknown.

State party officials estimated the outcome would probably show Newt Gingrich in second place, followed closely by Ron Paul, but for most of Sunday, they didn't have the hard votes to shore up their projections. Continued...