Speaking yesterday before a crowd of more than 30,000 in Madison, Wis., Al Gore stressed the importance of tackling global warming in one of the most spirited speeches he’s given all year. “If the big oil companies and the chemical manufacturers and the other big polluters were able to communicate a message to this state, they would say, ‘Vote for George Bush, or in any case, vote for Ralph Nader,'” Gore said, pledging to be a strong advocate for environmental protection. The Gore campaign is finally publicly acknowledging the threat posed by Nader and is overtly trying to woo progressive voters away from the Green Party nominee. A number of enviro organizations and other left-leaning interest groups are also trying hard to convince voters in swing states to back Gore over Nader. Friends of the Earth, which endorsed Bill Bradley in the Democratic primary and flirted with the idea of endorsing Nader in the general election, is now taking out newspaper ads in six swing states stating “There is a Grand Canyon of difference between Bush and Gore.” Despite pleas from a number of liberals, Nader refuses to back down from the race and continues to fight for votes wherever he can get them.