Obama was re-elected president in November 2012, defeating Republican nominee Mitt Romney, and was sworn in for a second term on January 20, 2013. During his second term, Obama has promoted domestic policies related to gun control in response to the Sandy Hook Elementary School shooting, has called for full equality for LGBT Americans, and his administration filed briefs which urged the Supreme Court to strike down the Defense of Marriage Act of 1996 and California's Proposition 8 as unconstitutional. In foreign policy, Obama has continued the process of ending U.S. combat operations in Afghanistan.