By far the most important domestic policy issue facing the next president will be fixing the health care system. The United States stands out among wealthy countries in not guaranteeing health insurance to its citizens.

Yet, even though many people cannot get access to care, we still pay more than twice as much per person as the average in other wealthy countries. And we have the worst outcomes. Only a severely over-medicated politician would claim we have the best health care system in the world.

As bad as the current system is, it keeps getting worse. The number of people who are uninsured year round is at 47 million and rising. The costs also keep rising. Companies are increasingly dropping insurance for their workers, or forcing workers to pick up a larger share of the bill. The explosion of health care costs is the basis for all the scare stories that budget hawks use to cut "entitlements." Since half of the country's health care costs are paid by the government, if we don't fix the health care system, it will eventually destroy the economy -- and also lead to very scary budget deficits.

So, what do the candidates offer? Following in the Republican tradition of referring to health care plans by the first name of their principle backer, let's see what the candidates propose.

John-Care is a plan to get rid of the employer-based insurance that most of us rely on presently. Senator McCain would eliminate the tax deductibility of employer-provided insurance, in effect, requiring employers who offer insurance to take money out of workers' paychecks for their tax liability on their health insurance.

Needless to say, this will make dealing with insurers even less attractive to businesses. Most employers will soon get out of the health insurance business and leave it to workers to buy their own plan. Toward this end, John-Care would give every worker a $2,500 tax credit, or $5,000 for a family.

This will not be sufficient to cover the cost of insurance for many families, especially those with serious health problems. Insurance companies don't like to insure people in bad health. While John-Care does provide a modest pool (at $7 billion to $10 billion) to help people with health problems to get insurance, this is a tiny fraction of what would be needed. Essentially, the McCain plan would undermine the current employer-provided system, and leave millions of people with health problems unable to buy insurance.

By contrast, Barack-Care would build on the current system. It would create a publicly run Medicare-type plan that any employer or individual can buy into. This would provide an additional option for people unhappy with their current insurance. However, those who are pleased with their current insurance would be able to stay with their plan under Barack-Care.

Barack-Care would also reform the private market, prohibiting insurers from charging more to people with health conditions, a rule that is already in place in several states. This would mean workers need not fear being unable to get insurance if they develop a serious illness and lose their job.

Barack-Care would also have subsidies for low- and moderate-income families to ensure they can afford to buy insurance. These subsidies would be financed by a fee assessed on employers who don't provide insurance. The basic story is that every employer (with a small business exemption) will have to contribute towards their workers' health care. They can either buy insurance directly, or they can contribute to a general fund to pay for insurance.

So, those are the basic outlines of the two candidates' health care plans. Senator Obama would build on the system that is already in place and offer people an additional option -- buying into a Medicare-type public plan. By contrast, Senator McCain wants to get rid of the current system of employer-provided insurance and force everyone to buy insurance as individuals.

In terms of health care policy, this is by far the sharpest difference between presidential nominees the country has ever seen. Hopefully, people will be aware of these distinctions when they cast their votes in November.