It could be the best choice for American voters if the Green Party didn't nominate controversial candidates like Cynthia McKinney. They should have endorsed Obama like other left-progressives like the Democratic Socialists of America. They also should have worked with Obama in 2008 for more environmental politics, They have great ideas but they need to stop nominating. The Green Party is socially liberal and fiscally center-left, with emphasis on environmentalism. Green Party advocates a new form of taxation - the carbon tax, a tax on emissions of carbon dioxide and greenhouse gases.