By Edith Honan and Kristina Cooke

(Reuters) - Newt Gingrich waged a charm offensive at a Tea Party gathering on Saturday, hoping to pick up support from conservative voters after fellow candidate Herman Cain suspended his presidential campaign.

Gingrich, the former Speaker of the House of Representatives in the 1990s, has taken the lead in the Republican presidential nomination race over former Massachusetts Governor Mitt Romney, according to several recent polls.

Many at a town hall event organized by the Staten Island Tea Party said they had not yet made up their mind about who to support but preferred Gingrich to Romney. A Reuters/Ipsos poll released this week showed Gingrich and Romney would benefit most from Cain quitting the race.

Gingrich has cast himself as an elder statesman of the Republican party, and he struck that tone on Saturday.

He described Cain, a former pizza executive who was beset by sex scandals, as "a powerful voice in the conservative movement for years to come." He added Cain's straightforward tax plan -- popular with fiscal conservatives -- had helped "elevate" the Republican debate.

Cain said on Saturday he would endorse a candidate for the Republican nomination soon but gave no hint who it would be.

Voting starts next month in the race to determine the Republican's presidential pick to run against President Barack Obama in November 2012.

"The Gingrich side has more passion than Romney supporters," said Daniel Castorina, 41, a member of the Staten Island Tea Party. "The Cain supporters... will all fall behind Gingrich."

Gingrich appeared relaxed and confident, cracking jokes -- mostly at Obama's expense -- and laughing off a disruption by an Occupy Wall Street demonstrator and a scuffle in the crowd over who got to ask the next question.

"I represent the world that works. Obama is the world that fails," Gingrich told the crowd of about 500 people.

Gingrich addressed many issues close to the heart of Tea Party voters, including small government and adherence to constitutional principles.

The Tea Party movement, which takes its name from the 1773 Boston tax rebellion against the British, has energized conservative voters and is considered a key constituency for winning the Republican nomination.

"I believe rights come from our creator... There is no being that can come between you and God and take those rights away," he told the crowd of about 500 people.

Ben Schulmann, 53, a Tea Party member from New Jersey, described Gingirch as "a Constitutionalist who will bring our nation back to its founding principles."

Many in the crowd said they believed Gingrich would perform well in a match-up against Obama.

"I don't see Newt getting pushed around," said Vincent Molinari, 45, a Brooklyn contractor.

Others in the crowd echoed that sentiment, saying Romney does not appear to be as strong. Romney has struggled to win over Tea party voters, many of whom say he has taken conflicting positions on many key issues, including health care and climate change.

"I don't like Mitt Romney. I don't think he has the charisma to get elected and I don't think he will fight hard enough," said Lou Taroli, 59, who described himself as a life-long Democrat and one-time supporter of Obama. He said he had made the two-hour trip from his home in Pennsylvania to attend the event.

"It all comes back to, I don't want four more years of Obama," he said.

Following the Gingrich event, hundreds of people lined up to purchase books by Gingrich and his wife, Callista, and to have them autographed.

"I think he's by far the most intelligent guy up there," said Steve Suity, 35, who said he has bought at least a dozen of Gingrich' many books.

(Editing by Greg McCune)