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Not yet a 2008 candidate, Fred Thompson energized young Republicans with a speech Saturday that was heavy on rhetoric and short on policy pronouncements. He branded Democrats as "the party of despair."

Chants of "Fred" and "Run, Fred, Run," greeted the actor and former GOP senator from Tennessee from many among the 350 people at the Young Republicans National Convention. The crowd interrupted his nine-minute speech with wild applause and mobbed him when he left.

"It makes me feel like the waters are pretty warm," Thompson said afterward. He has formed an exploratory committee to gauge support for a White House run and raise money. He is expected to announce presidential campaign plans to run soon.

Hours later, former Massachusetts Gov. Mitt Romney also addressed the crowd and spoke about foreign policy, Iraq, the economy, health care and other issues. Although he didn't have as much trouble working his way out of the room, the substance of his remarks impressed some undecided voters.

"He touched on a lot of different issues — the terrorists, immigration, families," said Brianne Goodwin, 24, of Chicago, who is undecided but leaning toward Romney. "Fred Thompson, he didn't really provide strong material."

Thompson has yet to join the 10-man Republican race, but he has soared in polls, taken in at least several million dollars, assembled a staff and visited early primary states New Hampshire and South Carolina.

Thompson's speech came on the heels of reports that a pro-abortion rights group hired him to lobby President George H.W. Bush's administration 16 years ago. At issue were attempts to ease a regulation that prevented clinics that received federal money from offering abortion counseling.

Thompson gave an oblique response when asked about the matter, first reported by the Los Angeles Times.

"I'd just say the flies get bigger in the summertime. I guess the flies are buzzing," said Thompson, who is considering running for president as a social conservative. He refused comment on whether he recalled doing the work.

His supporters did not seem bothered, citing policy stands by some of the leading GOP presidential contenders, including Romney, ex-New York City Mayor Rudy Giuliani and Arizona Sen. John McCain.

"Whatever choice do we have? Mitt Romney has been on both sides of the issue," said Paul Boyd, 26, of Memphis, Tenn. "Rudy Giuliani is 100 percent pro-choice. John McCain, at least for the first four years of the Bush term, was against whatever the president was for. Everybody has their flaws."

In his speech, Thompson fired up the crowd when he said he was the top target of The New York Times and Democratic presidential candidate Hillary Rodham Clinton. He said the United States was the greatest country, and that set the audience off, too.

"I'm getting tired of having to apologize for the United States of America around the world," Thompson said. "I'm tired of other people's perceptions that we need to apologize."

He said voters will not support Democratic candidates who are "driving over a left-wing cliff." Thompson added, "I don't think the people are going to turn the keys of this country over to the party of despair."

Kevin Fickert, a 22-year-old college student in Los Angeles who originally is from Massachusetts, said he liked Romney's leadership as governor but thinks Thompson has more appeal. "Thompson has this star power about him that I really like," Fickert said.

Not everyone at the convention was ready to join the Thompson bandwagon. Daniel Ruoss, 27, of Lauderhill said he is supporting Giuliani.

"Fred Thompson would not only have to hit a home run, he'd have to hit a grand slam for me," Ruoss said before the speech. Afterward, he said there was a lack of substance in the speech. "I would call it a double. I liked it, but we need more."

Romney was also well-received during his dinner speech. He, too, drew much of his applause by attacking Democrats. He repeatedly criticized Clinton on a number of issues, said former Sen. John Edwards denies that there's a war on terror, knocked Sen. Barack Obama's health care plan and poked fun at former Vice President Al Gore on the day Gore promoted Live Earth concerts to fight climate change.

"Here's an inconvenient truth Al Gore won't tell you about — there's one thing you can count on if America elects a Democratic president, and that's higher taxes," Romney said, referring to the climate change documentary featuring Gore.

Before arriving at the convention, Romney took questions from about 150 people in West Palm Beach. He said he would like to use the country's leading marketing minds to help sell the idea of American values in the Middle East.

"People will give up half a day's salary to get a Coca-Cola in some parts of the world. We market Coke well. We market McDonald's well. We market our rap music, our movies, our jeans," Romney said. "We market everything America sells brilliantly, but when it comes to marketing ourselves and what we stand for, we don't do a very good job of it."