WASHINGTON - U.S. Sen. Jim DeMint on Thursday accused President Barack Obama of trying "to sell socialism" to Americans and of leading a government "teetering toward tyranny" in a hard-hitting speech to conservative activists gathered from across the country.
More than 1,000 delegates to the annual convention of the American Conservative Union gave DeMint a rousing hero's welcome, urging him to run for president and delivering a sustained standing ovation.
David Keene, head of the conservative advocacy group, noted that DeMint is the only senator with "a perfect 100 rating" as he introduced the South Carolina Republican to the raucous crowd.
"Jim DeMint is articulate, he's a believer, he's one of us and he's tough!" Keene said to enthusiastic roars of support.
DeMint addressed the group twice - first introducing Marco Rubio, a Florida Republican candidate for the U.S. Senate, and later on his own behalf.
DeMint, in the final year of his first Senate term, criticized the federal bailouts of banks, automakers and other large companies.
"The federal government is assaulting almost every sector of our free-market economy at a time when I fear America is teetering toward tyranny," he said.
DeMint accused Obama of delivering "false hope and empty promises." The senator mocked the president's charisma and oratory skills.
"I hope Americans will expect more from their next president than a great speech," he said. "You can't govern from a Teleprompter. Just because you are good on TV doesn't mean you can sell socialism to freedom-loving Americans."
Democrats responded sharply to DeMint's attacks.
"At a time when Sen. Jim DeMint should be focused on addressing the economic challenges facing South Carolinians, he's busy trying to get national television attention," said Deirdre Murphy, a spokeswoman for the Democratic Senatorial Campaign Committee.
"Sen. DeMint should start caring more about his state than national media opportunities," Murphy said.
Some of the conservative faithful in DeMint's audience encouraged him to seek national office.
When DeMint cited the stakes in the 2012 presidential election, one activist yelled out, "DeMint for president!" and drew cheers of support.
DeMint, who broke into the national spotlight in winter 2007 for blocking $1 billion in spending earmarks, also criticized fellow Republicans in his speech.
"There is still a struggle within the Republican Party about who we are and what we stand for," he said. "It's really a fight between those who take their constitutional oath seriously and those who don't."
DeMint gloated over his backing of Rubio, a Cuban-American former Florida House speaker who is challenging Gov. Charlie Crist for a U.S. Senate seat.
In impromptu remarks that departed from his prepared text, DeMint recalled meeting last year with other Republican senators who are backing Crist.
"They told me Mario had no chance and he would drop out of the race," DeMint said.
DeMint said Rubio has closed a 30-point gap in opinion polls and is now running even with Crist.
"The Washington establishment laughed it off," DeMint said of the GOP reaction to his endorsement of Rubio. "Well, they're not laughing now!"
Rubio thanked DeMint for his early support.
"Jim DeMint believed in me when the only people who believed in me lived in my house," Rubio said.
Following Rubio to the stage, DeMint said he'd been deeply moved by the Floridian's account of his parents' hard life after they emigrated from Cuba to the United States.
"I was standing backstage with tears in my eyes," DeMint told the crowd.
DeMint promoted his book, "Saving Freedom," published last year, his Senate Conservatives Fund and his bill requiring a balanced budget while imposing a one-year moratorium on earmarks.
"With our country drowning in debt, if we can't give up pork for one year and won't even try to balance the budget now, there's no reason to think we'll ever do it," he said.
DeMint's leadership PAC has raised more than $1.2 million for Senate candidates. He's doling out funds to Rubio and to Republican primary candidates in California, Texas and Pennsylvania.
DeMint refused to back down from past controversial comments.
"I've been criticized by some of my Republican colleagues for saying I'd rather have 30 Republicans in the Senate who believe in the principles of freedom than 60 who don't believe in anything," he said. "Let me make myself even clearer: I'd rather have 30 Marco Rubios than 60 Arlen Specters."
The Pennsylvania senator switched parties and became a Democrat last year after DeMint told him he would back former U.S. Rep. Pat Toomey in the Keystone State's 2010 Republican primary.
DeMint brought up his widely criticized slight of Obama last year, when he told conservative activists opposed to expanded government health insurance: "If we're able to stop Obama on this, it will be his Waterloo. It will break him."
DeMint ended his address by echoing that controversial comment.
"Frankly, sometimes I feel like I'm trying to hold back the tide, and the constant fighting can be tiresome," he said. "If I couldn't come here every year and plug into (your) renewable energy source, I wouldn't have the strength to even show up at Waterloo, much less win the battle."