WASHINGTON — It's health care brinksmanship, with hundreds of billions of dollars and the well-being of millions of people at stake.

President Barack Obama's health care law expands Medicaid, the federal-state health program for low-income people, but cost-wary states must decide whether to take the deal.

Turn it down, and governors risk coming off as callous toward their neediest residents. Not to mention the likely second-guessing for walking away from a pot of federal dollars estimated at nearly $1 trillion nationally over a decade.