According to an analysis from the Los Angeles Times, the states with the greatest need to expand Medicaid also, unfortunately, have Republican leaders who are refusing to participate. This opposition could leave millions of the nation's poorest residents without insurance coverage, and will likely widen the divide between the nation's healthiest and sickest states.

Colon cancer deaths in states opposing Medicaid expansion, for example, are an average of 16% higher than in pro-expansion states, according to a Los Angeles Times analysis of state health data.

Deaths from breast cancer are 8% higher on average in anti-expansion states. And adults under 65 are 40% more likely on average to have lost six or more teeth from decay, infection or gum disease.

Medicaid by itself may not close those gaps, which also reflect income and education disparities. And the program's conservative critics, who contend it could ultimately sap state budgets, say poor Americans would be better helped by alternative strategies, including limits on government medical aid to encourage people to take responsibility for their own healthcare.

"Government assistance should not be an entitlement. Government assistance should not be a lifestyle," said Michigan House Speaker Jase Bolger, a Republican who has called for a complete overhaul of the state's Medicaid program, including a four-year limit on benefits for nondisabled adults. "Government assistance should be a temporary hand up. It should be a way to improve people's lives, not trap them in dependency."

Yet most state leaders who are fighting the Medicaid expansion have advanced few alternative plans to tackle their states' health shortfalls. That means that, at least in the short term, America's unhealthiest states could fall even further behind as the Affordable Care Act is implemented.

"Many states may be missing a real opportunity to reduce some of the big differences we see across the country in health," said Cathy Schoen, a health economist at the nonprofit Commonwealth Fund who has studied variations between states.

Residents of many of those states, those in the Deep South, would really love to see Medicaid expansion, a new survey suggests. Families USA polled in Alabama, Georgia, Louisiana, Mississippi and South Carolina -- places where the Medicaid expansion would cover millions of uninsured people -- and found that 62 percent of respondents support Medicaid expansion.

Not all Republican led states will be left behind; several high-profile conservative Republican governors, including John Kasich (Ohio), Rick Scott (Fla.), Jan Brewer (Ariz.) and Chris Christie (N.J.) have supported the expansion.