George Washington
At the end of his second term, Washington retired for personal and political reasons, fatigued and disgusted with personal attacks, and to assure a truly contested presidential election could be held. He did not feel bound to a two-term limit, but his retirement ultimately set precedent. The two-term limit to the presidency was formalized with the 1951 adoption of the Twenty-second Amendment to the United States Constitution. Washington is often credited with setting the principal of a two-term presidency, but it was Thomas Jefferson who first refused to run for a third term on political grounds.
Modern liberalism in the United States
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, and has called for full equality for LGBT Americans, while his administration has filed briefs which urged the Supreme Court to strike down the Defense of Marriage Act of 1996 and California's Proposition 8 as unconstitutional.