Ralph Nader’s contention that there is no difference between Al Gore and George W. Bush is “irresponsible” and his campaign threatens the environment by potentially tipping the election toward Bush, writes Robert F. Kennedy, Jr., in an op-ed in today’s New York Times. Kennedy, a lawyer for the Natural Resources Defense Council and one of Gore’s most powerful enviro allies, says that Gore deserves credit for protecting the environment against the “Gingrich Congress,” fighting against global warming, and pushing for stronger air and land protections. Kennedy believes that a vote for Nader is effectively a vote for George W. Bush, who has a “famously abysmal environmental record,” and he argues that enviros who join Nader’s “personal crusade risk marginalizing the conservation movement.”