Obama has acted on his own, to increase mileage standards and impose pollution control on future power plants. More such executive action is likely; a law is not.___ Gun control: The promise: Ban assault weapons and high-capacity ammunition magazines, expand background checks, and more, a postelection pledge made after the massacre at Sandy Hook Elementary School in Newtown, Conn. Prospects: Obama said he would "put everything I've got into this." His everything wasn't enough. Entrenched support for gun rights and a powerful campaign by the National Rifle Association blocked efforts to pass a single aspect of Obama's package, the first attempt to significantly change the nation's gun laws in over two decades. Polling found as many as 90 percent of those questioned supported expanded background checks, but even that fell short in the Democratic-controlled Senate. ___ Health care: The promise: Ensure access to affordable insurance for all and no gutting of Medicare or Medicaid. Prospects: Obama is likely to achieve his goal of extending coverage to the uninsured. Affordability is another question. Costs are expected to go up, not down, contrary to what Obama promised in his first term. Some Medicare cuts Obama is willing to enact would hit beneficiaries. Well-to-do seniors and growing numbers of upper middle-class retirees could face higher monthly premiums. ___ Immigration: The promise: Overhaul the immigration system to provide eventual citizenship to those who came here illegally, tighten borders and smooth legal immigration. Prospects: Obama failed to deliver on his first-term promise to rework immigration law. His chances of pulling that off are much better now. Even with a bipartisan Senate group having released legislation to accomplish those goals, however, success is not certain. Even so, the political climate is ripe for change thanks to a shift in Republican attitudes in 2012, when Latino and Asian voters backed Obama in record numbers.?