The health care debate is coming to state capitals. The issue is whether or not to expand Medicaid, the federal-state health program for low-income people. More than 15 million uninsured people are expected to gain coverage through Medicaid under President Barack Obama's health care law. States are free to turn down the expansion, but the choice isn't easy. Governors worry about costs. But if they say "no," they risk coming off as callous toward their neediest residents. Not to mention the second-guessing for walking away from a pot of federal dollars estimated at nearly $1 trillion nationally. The coverage expansion doesn't happen until 2014, but the debate in state capitals starts now. It's health care brinksmanship, with billions of dollars and the well-being of millions of people at stake.