By Ros Krasny

LAS VEGAS (Reuters) - What happens in Vegas, stays in Vegas. And Republican Newt Gingrich certainly will hope the disarray that marred his campaign in Nevada last week will not doom his White House bid as he heads toward a possible Super Tuesday last-stand next month.

Stinging losses to Mitt Romney in Florida and Nevada within a week have sucked much of the energy from the former House speaker's shot at the Republican nomination to challenge President Barack Obama in the November 6 general election.

Gingrich's upset win in South Carolina on January 21 seems a lifetime ago. The candidate has appeared tired and fed-up at the very time he needs to recharge his campaign to win voters and donors with Super Tuesday, when 10 states hold nominating contests, looming on March 6.

Gingrich, 68, campaigned hard in Florida, possibly to the point of exhaustion, ran chronically late to events and cut short some speeches. In Nevada he appeared sparingly and struggled to keep up with the issues of the day, such as the positive January jobs report, a possible political game-changer that he had not seen five hours after its release.

The negative television ads so successful in siphoning Gingrich support in Florida followed him to Nevada. Romney's well-funded campaign, and backing from a political action committee run by Romney supporters, will no doubt continue the blitz.

There might be a point beyond which Gingrich, who many observers think entered the presidential race mostly to burnish his reputation as a conservative elder-statesman, can no longer stomach the daily attacks.

Republican strategist Ford O'Connell said Gingrich had lost control of his emotions at times. "Gingrich should not have let Romney get into his head," O'Connell said. "That was a killer. When he's angry, he is his own worst enemy."

NEWT'S NOTORIOUS STAYING POWER

Indeed, Gingrich does best when he displays faux anger - such as in the South Carolina debates, when he twice attacked the moderators with a theatrical flourish - but worse when he actually is angry.

"Gingrich felt very wronged by the Romney campaign. Is it worth staying in the race to prove a point?" said Krystal Ball, a Democratic strategist. "But I would say, if anyone has staying power, it's Newt Gingrich."

Ball said the torrent of negative television advertising in Florida - the vast majority directed at Gingrich - was unprecedented.

"It was also quite successful," she said.

The commercials focused on Gingrich's ethics violations in Congress and his work as a consultant for mortgage giant Freddie Mac. They also mocked his claim that he was a close associate of president and conservative hero Ronald Reagan, which has been one of Gingrich's key campaign themes.

"Among the rank and file, the notion that Newt Gingrich was the conservative leader in Congress in the 1990s was very well established. The Romney commercials really attacked that," said Charles Franklin, visiting professor of law and public policy at Marquette University Law School.

"In Congress, Newt has generated a lot of ideas that were important to the Republican Party," Franklin said. "Romney's comments cut to Newt's reputation as a guy who creates big ideas. They cut right to his core."

In an emotional speech to faith leaders in Las Vegas on Friday night, Gingrich let out some of the hurt. "I'm going to speak from my heart for a minute," he said. "I am ashamed by the negativity and dishonesty that has marked this campaign."

But on Saturday, in a defiant news conference after the Nevada vote, Gingrich said he had no choice but to go negative to keep pace with Romney's "level of ruthlessness and the level of dishonesty."

GOT DISCIPLINE?

Strategists said Gingrich's biggest challenge is that he never laid the foundation of a campaign in the first place, especially after much of his staff quit in early June.

"The best opening for him between now and Super Tuesday is money, discipline and organization," O'Connell said. Continued...