File photo of U.S. President Obama delivering remarks on Obamacare at an Organizing for Action grassroots supporter event in Washington

U.S. President Barack Obama delivers remarks on the Affordable Care Act, commonly known as Obamacare, at an Organizing for Action grassroots supporter event in Washington, in this November 4, 2013, file photo. New Year's Day will bring a fresh test for President Barack Obama's healthcare overhaul, as hundreds of thousands of Americans will begin to use the program's new medical coverage for the first time. REUTERS/Jonathan Ernst/Files (UNITED STATES - Tags: POLITICS HEALTH)