Ron Paul, left, and Newt Gingrich, right, are staying in the GOP presidential nomination race despite poor poll numbers.

Story highlights

Newt Gingrich can still win the nomination and is determined to fight on, an aide says

A majority of Republicans want Gingrich and Ron Paul to drop out, a new poll says

Mitt Romney holds a 2-to-1 lead over Rick Santorum in the delegate count

Gingrich, Paul and Santorum say they will stay in the race

Washington CNN  — 

Republican presidential candidate Mitt Romney picked up another major endorsement Friday when conservative favorite Wisconsin Rep. Paul Ryan, whose state votes Tuesday, called Romney “the right person for the job.”

Joe DeSantis said Gingrich’s decision to lay off staff and replace his campaign manager was a reorganization that would enable him to fight on to the Republican National Convention in the summer and win the nomination there.

With calls increasing for some or all of them to drop out, challengers to Republican presidential front-runner Mitt Romney say they intend to keep battling until the nomination gets settled.

But they want conservative challenger Rick Santorum to stay in the race.

The poll, conducted over the weekend, showed that about six in 10 Republicans want Gingrich and Paul to halt their campaigns, while a similar number supported Santorum continuing his bid.

DeSantis said the poll “showed that Gingrich dropping out of the race would help Mitt Romney dramatically more than it helps Rick Santorum.”

This would “virtually guarantee Mitt Romney the nomination,” he said, as he urged conservatives to rally behind Gingrich to keep the former Massachusetts governor from victory.

According to CNN’s latest estimate, Romney has secured 569 delegates and needs 575 more to reach the 1,144 required to clinch the GOP nomination.

Santorum, the former Pennsylvania senator, has 262 delegates, with Gingrich at 136 and Paul at 71.

Meanwhile, a big Gingrich backer said the former House speaker was nearing the end.

Meanwhile, the staff layoffs and reorganization reflect the need to plan around the “financial realities” of the campaign, DeSantis said.

Gingrich’s campaign is being driven by small donations, he said, with 95% of its 176,000 donors giving less than $250 but a “steady stream” of donations still coming in.

Gingrich’s team has struggled to keep pace with Romney’s high spending in key states.

Romney took his campaign to the late-night airwaves Tuesday, making an appearance on “The Tonight Show” with host Jay Leno.

After cracking a few jokes, Romney and Leno settled into a discussion on health care. Many conservatives are uncomfortable with a health care reform package signed by Romney when he was governor of Massachusetts. The Obama administration later modeled – in part – its health care reform law on the Massachusetts plan.

Despite the poll showing long odds, none of the three trailing candidates seems close to giving up.

Santorum challenged the delegate math, telling CNN’s Wolf Blitzer on Monday that the Republican race was likely to continue until the party’s national convention in August in Florida.

“There may be someone with what they say are enough delegates, but as you also know, Wolf, a huge number of delegates are uncommitted,” Santorum said. “They may be for me, or they may be for Mitt, but they’re technically uncommitted, and therefore you can’t put them in your column.”

Gingrich said Tuesday that he would drop out if Romney, the former Massachusetts governor, reaches the 1,144-delegate threshold to claim the nomination. However, Gingrich added he doubted that would happen before the convention.

“Gov. Romney is the front-runner but is a long way from a majority,” Gingrich said at Maryland’s capitol building in Annapolis. “If (Romney) does get, by the time Utah votes on the 26th of June, if he gets a majority, obviously I will support him and will be delighted to do anything I can to help defeat Barack Obama.”

Paul also sounded committed to staying in the race, telling CNN’s “Piers Morgan Tonight” on Monday that “it’s way too soon for you to write anybody off.”

“Why should we just throw in the towel because people like you say, ‘Hey, throw in the towel’? ” Paul asked.

According to the new poll, 36% of Republicans support Romney for the nomination, and 26% back Santorum. It was a different story in February, when the two men were effectively tied in CNN’s last national survey, with Santorum at 34% and Romney at 32%.

The survey seemed to dispel the commonly held notion that Gingrich and Santorum were vying for conservative support against the more moderate Romney. According to the poll, most of Gingrich’s supporters said Romney was their second choice, rather than Santorum.

“If you recalculate the GOP horse race using the Gingrich voters’ second choice, Romney’s lead over Santorum grows to 15 percentage points – 45% for Romney and 30% for Santorum – compared to the 10-point margin Romney currently has in the four-man field,” CNN Polling Director Keating Holland said.

The primary calendar resumes April 3 with contests in Wisconsin, Maryland and the District of Columbia. A three-week break follows until April 24, when New York, Pennsylvania, Delaware, Connecticut and Rhode Island vote.

Those contests in more moderate states in the Northeast, Mid Atlantic and Midwest appear to favor Romney over Santorum, with the possible exception of Pennsylvania, which Santorum represented in Congress for nearly two decades.

CNN’s Paul Steinhauser, Tom Cohen and Mark Preston contributed to this report.