Seeking to defuse a potential showdown over a key part of the new healthcare law, the Obama administration moved Friday to let states, rather than the federal government, define which medical benefits insurance companies will have to offer consumers starting in 2014. That allows state leaders to retain more control of health insurance even as the law extends a new federal guarantee that all Americans can get coverage, even if they are sick. "This is significantly more state-flexible and friendly than many would have expected," said Alan Weil, head of the National Academy for State Heath Policy. It remains unclear,...