The Tea Party movement burst onto the scene a year ago in protest of the economic stimulus package, and its supporters have vowed to purge the Republican Party of officials they consider not sufficiently conservative and to block the Democratic agenda on the economy, the environment and health care. But the demographics and attitudes of those in the movement have been known largely anecdotally. The Times/CBS poll offers a detailed look at the profile and attitudes of those supporters.

Their responses are like the general public’s in many ways. Most describe the amount they paid in taxes this year as “fair.” Most send their children to public schools. A plurality do not think Sarah Palin is qualified to be president, and, despite their push for smaller government, they think that Social Security and Medicare are worth the cost to taxpayers. They actually are just as likely as Americans as a whole to have returned their census forms, though some conservative leaders have urged a boycott.

Tea Party supporters’ fierce animosity toward Washington, and the president in particular, is rooted in deep pessimism about the direction of the country and the conviction that the policies of the Obama administration are disproportionately directed at helping the poor rather than the middle class or the rich.

The overwhelming majority of supporters say Mr. Obama does not share the values most Americans live by and that he does not understand the problems of people like themselves. More than half say the policies of the administration favor the poor, and 25 percent think that the administration favors blacks over whites — compared with 11 percent of the general public.

Image Walter Maciel, center, of Tewskbury, Mass., at the Tea Party rally Wednesday on Boston Common. Credit... Gretchen Ertl for The New York Times

They are more likely than the general public, and Republicans, to say that too much has been made of the problems facing black people.