But Mr. DeMint distances himself from both parties. As he put it, “None of us wants the people who ran cash for clunkers or who cleaned up after Katrina to be between us and our doctors.” He is sensitive to the accusation of being an obstructionist on health care and has come up with a plan of his own. It would give vouchers ($2,000 for individuals and $5,000 per family) to those not covered by their employers, let people shop in other states for insurance, limit malpractice suits and repeal the bailout to troubled financial institutions so that it would not add to the deficit. Mr. DeMint does not get too many questions about it, but it has drawn some criticism. Frank Knapp, chief executive of the South Carolina Small Business Chamber of Commerce, said that the plan had no sustainable financing mechanism and that Mr. DeMint came up with it only to give himself credibility in criticizing Mr. Obama’s plan. The concept of allowing interstate sales of health insurance has never gone very far. Sandy Praeger, the insurance commissioner in Kansas and past president of the National Association of Insurance Commissioners, said such a plan would destabilize the nation’s insurance market and hurt consumers. It would allow insurance companies to cherry-pick young, healthy people and offer them lower premiums, Ms. Praeger said, while leaving higher risk people in a smaller pool, forcing up their premiums or leaving them unable to find coverage at all. Mr. DeMint’s town-hall-style meetings, where he promotes his new book, “Saving Freedom: We Can Stop America’s Slide into Socialism,” tend to be more like cheerleading sessions than the angry confrontations faced by lawmakers elsewhere.