Des Moines, Iowa ? Democratic front-runner Sen. Hillary Clinton offered a plan Monday to provide health insurance to all Americans, positioning all of the party’s major candidates as advocates for ambitious programs of either universal or near-universal health care.

Thirteen years after presiding as first lady over a failed attempt at a national health care plan, Clinton presented a plan that avoided some of the political pitfalls that contributed to the demise of the Clinton administration’s health plan in 1994. Unlike her previous effort, she would allow Americans satisfied with their current health insurance plans to continue their coverage and would avoid a large new federal bureaucracy.

The groundwork is now laid for a general-election contest that will provide a clear choice between the two parties on health care.

Republican candidates offer tax credits to lower the cost of health insurance, with private markets relatively undisturbed, while Democratic candidates urge a greater government role in guaranteeing availability of health insurance for all. The Democratic candidates would pay for their programs by eliminating Bush administration tax cuts for high-income earners and through projected savings from new efficiencies they say their plans would create in the health care system.

Clinton would offer federal subsidies to businesses and individuals to reduce the cost of health care, particularly for lower-income families, while imposing a new federal requirement that every American purchase health insurance coverage.

Her approach echoes state-based health care plans proposed by Republican Gov. Arnold Schwarzenegger of California and then-Gov. Mitt Romney of Massachusetts that require individuals to buy health insurance much as many states now require drivers to buy auto insurance.

Her Democratic rivals also borrow heavily from the Republican governors’ approach, though unlike Clinton and John Edwards, Sen. Barack Obama, D-Ill., would mandate coverage only for children, not adults. As with the California and Massachusetts state plans, the major Democratic candidates would all rely on individuals to obtain coverage by buying it or through their employers, provide subsidies for coverage and allow the public access to government-based insurance programs.

“All of the Democratic candidates have now come out with big plans,” said Drew Altman, president of the Kaiser Family Foundation, a nonpartisan health care policy foundation. “Those plans in the end are going to look more similar than different to Democratic voters in the primaries and, despite differences, are more similar than different.”