Nader, 73, said most people are disenchanted with the Democratic and Republican parties due to a prolonged Iraq war and a shaky economy. The consumer advocate also blamed tax and other corporate-friendly policies under the Bush administration that he said have left many lower- and middle-class people in debt.
"You take that framework of people feeling locked out, shut out, marginalized and disrespected," he said. "You go from Iraq, to Palestine to Israel, from Enron to Wall Street, from Katrina to the bumbling of the Bush administration, to the complicity of the Democrats in not stopping him on the war, stopping him on the tax cuts."
"In that context, I have decided to run for president," Nader told NBC's "Meet the Press."
Nader also criticized Republican candidate John McCain and Democrats Barack Obama and Hillary Rodham Clinton for failing to support full Medicare for all or cracking down on Pentagon waste and a "bloated military budget. He blamed that on corporate lobbyists and special interests, which he said dominate Washington, D.C., and pledged in his third-party campaign to accept donations only from individuals.
"The issue is do they have the moral courage, do they have the fortitude to stand up to corporate powers and get things done for the American people," Nader said. "We have to shift the power from the few to the many."
