Michael Steele, in remarks at the National Press Club, also said the president, House Speaker Nancy Pelosi and key congressional committee chairmen are part of a "cabal" that wants to implement government-run health care.
"Obama-Pelosi want to start building a colossal, closed health care system where Washington decides. Republicans want and support an open health care system where patients and doctors make the decisions," Steele said.
Asked if Mr. Obama's health care plan represented socialism, Steele responded: "Yes. Next question."
Mr. Obama has repeatedly said he does not favor a government-run health care system. Legislation taking shape in the House envisions private insurance companies selling coverage in competition with the government.
Even so, numerous Republicans in Congress continue to level the accusation at Mr. Obama and congressional Democrats, and Steele did so in sharply critical terms.
"Many Democrats outside of the Obama-Pelosi-Reid-Waxman cabal know that voters won't stand for these kinds of foolish prescriptions for our health care. We do too. That's why Republicans will stop at nothing to remind voters about the risky experimentation going on in Washington," the party chairman said. Harry Reid, D-Nev., is Senate majority leader; Rep. Henry Waxman, D-Calif., is chairman of the House Energy and Commerce Committee.
Republican officials said they were supplementing Steele's speech with a round of television advertising designed to oppose government-run health care. The 30-second commercial, titled "Grand Experiment," criticizes recent government aid to the auto industry and banks as "the biggest spending spree in our history" and warns similarly of "a risky experiment with our health care."
The GOP ads show children who presumably would be burdened as adult taxpayers with the cost of the health care overhaul. The commercials are being broadcast in Nevada, home of Senate Majority Leader Harry Reid, as well Arkansas and North Dakota, states represented in the Senate by moderate Democrats. The ad is also being posted on the Internet, in coordination with a grass-roots campaign.
Separately, the insurance industry, which challenged President Bill Clinton's health care effort in the early 1990s, launched its first TV ads of this year's health care fight. The multimillion-dollar campaign, being aired nationally on cable stations, restates the industry's support for an overhaul that provides universal coverage and its offer to cover people who are already sick. The ad campaign does not mention the insurers' strong opposition to creating a government-run insurance option.
In his speech, Steele broadened his attack beyond health care to question Mr. Obama's truthfulness.
The president "tells us he doesn't want to spend more than we have, he doesn't want the deficit to go up, he doesn't want to live off borrowed money. But he also told us he didn't want to run an auto company. President Obama justifies this spending by saying the devil made him do it. He doesn't want to spend trillions we can't afford, but he says he just can't help it," Steele said in the prepared excerpts.
The Republican chairman is making his speech at a time when Mr. Obama is struggling to advance his trademark health care proposal after a period of evident progress. Two of three House committees have approved their portions of the bill, while one of two Senate panels have acted.
But conservative Democrats have raised objections to some elements of the legislation, and efforts in the Senate to reach a bipartisan agreement have yet to bear fruit. Mr. Obama's attempt to impose an early August deadline on both the House and Senate for passage of legislation is in jeopardy.
White House officials spent Sunday defending Mr. Obama's health care proposals and stressing that Congress has not yet written the final draft of legislation that would dramatically reshape how Americans receive health care. Instead, they said, Republicans - and even some Democrats - should wait until a final bill takes form.
Getting it done by August, though, appeared to be pushed back. Administration officials said they still have a goal for the Senate and the House to pass separate bills before an August recess, leaving reconciliation of their differences for September or later. But they slid away from a once-firm do-it-this-summer demand.
"We think we can make that. We're working towards that," White House budget director Peter Orszag said. "And we have to remember, there are some who are advocating the delay simply because they don't have anything to put on the table. ... There are those who are advocating delay just as a desperation move to try to kill this."
Time would appear to be on the Republicans' side, however. A Washington Post-ABC News survey released Monday shows approval of Obama's handling of health care reform slipping below 50 percent for the first time. The poll had a margin of sampling error of plus or minus 3 percentage points.