PORTLAND, Ore. (AP) -- The Obama administration is buying into an ambitious health care initiative in Oregon, announcing Thursday it has tentatively agreed to chip in $1.9 billion over five years to help get the program off the ground. Oregon hopes to prove that states can save billions on Medicaid without sacrificing the quality of health care. Gov. John Kitzhaber's plan would invest in preventive care to keep patients healthy so they don't need expensive hospitalizations. "If this works, I think other states are going to be looking at this as a way to manage that patient population," said Kitzhaber,...