The Green Party is an essentially left-wing political party in the United States which places a strong emphasis on environmentalism. It supports many liberal social policies, as well as advocating moving politics to the grassroots and community level. It also supports debt reduction, a conservative principle, though it generally supports doing this by raising taxes on the upper income brackets and cutting military spending.
There are other Green parties throughout the world, though most, if not all act independently of each other.
The Green Party's nominee for President in 1996 and 2000 was Ralph Nader. It was Ralph Nader's candidacy as the Green Party nominee in 2000 that reportedly split enough votes in Florida to enable George W. Bush to defeat Al Gore there, and that became the margin of Bush's victory for the entire nation.
The Green Party 2004 candidate was David Cobb, with Pat LaMarche as his running mate. In 2008, the Green Party nominee was ultraliberal former Congresswoman Cynthia McKinney of Georgia. Their 2012 candidate is Jill Stein.