WASHINGTON -- The environment has played a tangible, though indecisive and often contradictory, role in the presidential primaries so far.
Paul E. Tsongas' support for nuclear power almost robbed him of victory in the Maine caucuses, but it did not stop him from winning handsomely in the Maryland primary.
Arkansas Gov. Bill Clinton's rivals have hammered him on his state's sorry environmental record. But it's Flowers, not flora, that raised questions about his electability.
The strong environmental message in Edmund G. "Jerry" Brown Jr.'s "insurgency campaign" clinched his win in the Colorado primary and gave him a near-upset in Maine, analysts say. But it brought him no joy in Florida, despite Floridians' deep-seated concerns for environmental issues like wetlands protection.
President Bush, campaigning ahead of yesterday's Michigan primary, took an anti-environmental approach: portraying a congressional attempt to raise fleet fuel efficiency standards as job-threatening and saying he would not sign legislation "that will destroy the auto industry and cost American jobs."
Mr. Bush rolled to victory in 1988 with a promise to be the "environmental president." But a lot has changed since then, most notably the national economy -- a fact made vividly apparent in November 1990 when California voters, choosing economic security over environmental well-being, rejected "Big Green," a sweeping catalog of environmental initiatives that would have been enormously expensive to enact.
Nonetheless, the president continues to face criticism on environmental issues, from environmentalists, who say he discounts pollution controls in favor of oil, nuclear and big business, and from conservatives like rival Patrick J. Buchanan, who sneer at his endorsement of restrictive legislation such as the Clean Air Act.
In fact, it is conservative pressure, environmentalists say, that has stonewalled the Environmental Protection Agency's efforts to regulate parts of the act.
In the current election campaign, too, the conservatives seem to have been more successful than the environmentalists in influencing Mr. Bush's position. But analysts say there could be a few twists and turns on the road to Nov. 3 that could draw the environment back to the spotlights, if only fleetingly.
One of these could be the June environmental summit in Rio de Janeiro, Brazil, which more than 100 heads of state have already pledged to attend. Mr. Bush is the only head of a major industrialized nation who has not yet agreed to go. But administration officials have hinted that the president may yet do so.
Under pressure from European nations and environmental groups, the United States -- the world's largest emitter of carbon dioxide, allegedly the main cause of man-made global warming -- appears grudgingly to have reversed policy recently and agreed to consider reducing carbon emissions. But some administration officials still maintain that an international carbon reduction treaty would hamper U.S. industrial competitiveness.
Mr. Bush, meanwhile, has already been hammered by his Democratic opponents for not taking a lead in the international environmental initiative. If he does decide to go to Rio, analysts say, he will have to beware of looking like an electioneering Johnny-come-lately. For now, though, the environment has been largely eclipsed by economic and health concerns, analysts say, though they are quick to add that it remains a "hidden factor" that could pop up at any time.
Thomas E. Mann, director of governmental issues at the Brookings Institution, said the environment now appears to be "a peripheral issue."
"In terms of sway in the primaries [the environment] is just not that big a deal," said John Shanahan, spokesman for the Heritage Foundation. "Most people are too mesmerized by the horse race to be concerned with certain issues.
"When it will count is in the presidential runoff," said Mr. Shanahan, "because that's when people expand their interests and these things become important."
Mr. Bush, who described himself as a "Teddy Roosevelt environmentalist" in 1988, did not utter a word about the environment in this year's State of the Union speech, the unofficial springboard for his re-election campaign.
Even Mr. Brown, a former California governor and probably the most environmentally committed candidate, has tended to emphasize the economic benefits of cleanups and non-polluting technology instead of simply appealing to environmental altruism win him votes.
It's not that the candidates, with the exception of Mr. Buchanan, have nothing to brag about environmentally. The League of Conservation Voters says that each of the Democrats, and even Mr. Bush, can point to something he has done, or stands for, that would improve the world.
Each also has a weak point, something that can be attacked by the others. Just how successful that is, analysts say, depends on where and how the attack is carried out.