In August 2011, Stein gave indication that she was considering running for President of the United States with the Green Party in the 2012 national election. She indicated in a published questionnaire that she had been asked to run by a number of Green activists and felt compelled to consider the possibility after the U.S. debt-ceiling crisis which she called "the President’s astounding attack on Social Security, Medicare and Medicaid – a betrayal of the public interest...". In the survey, she suggested that she would announce her intentions by the end of September 2011. Stein later stated that she would announce her intentions on October 24.
On October 24, 2011 Stein launched her campaign at a press conference in Massachusetts, saying "We are all realizing that we, the people, have to take charge because the political parties that are serving the top 1 percent are not going to solve the problems that the rest of us face, we need people in Washington who will refuse to be bought by lobbyists and for whom change is not just a slogan".
In December 2011, Wisconsin Green Party leader Ben Manski was announced as Stein's campaign manager.