The outpouring of opposition to the World Trade Organization has severely shaken the free-trade wing of the Democratic Party, threatened grass-roots union support for Al Gore's presidential campaign and potentially undermined the party's hopes of retaking the House.

The spectacular collapse of last week's WTO talks in Seattle could have a major impact on American politics next year, particularly within the Democratic Party, where trade has become a major fault line in a party struggling to unify before crucial national elections, according to politicians, labor leaders and analysts.

Democrats are counting on a big grass-roots effort by labor unions, environmental groups and other foes of free trade to fuel their drive to win the House and retain the White House. But union enthusiasm for Democrats, particularly Vice President Gore, could dim as the feeling grows that the administration has been working against labor's interest, both during the Seattle trade talks and the recent decision to invite China into the WTO.

Some labor officials point to the political experience of 1994: The administration's support for the North American Free Trade Agreement with Mexico and Canada dampened union turnout in midterm elections, when the Republicans took over both houses of Congress.

Mike Mathis, government affairs director for the Teamsters, cited Gore in contending that there will be a substantial problem "motivating members for a guy who pushed through NAFTA and . . . for China" in the WTO.

Karl Rove, chief strategist in the GOP presidential campaign of Texas Gov. George W. Bush, offered a similar argument from a different ideological perspective. "Seattle hurt [Democrats] big time," he said. "There is an international wing and a protectionist wing in the Democratic Party, and how are they going to paper that over in the general election?"

John J. Sweeney, president of the AFL-CIO and the orchestrator of the labor federation's endorsement of Gore, said the consequences of the Seattle debacle "remain to be seen." But he expressed doubt that Gore will be seriously damaged among his union supporters.

Still, the collapse of the trade talks was a setback in the Clinton administration's efforts to forge a more liberal trade climate. The administration and other members of the World Trade Organization--a Geneva-based institution set up four years ago to enforce free-trade rules among its 135 member nations--had been hoping to agree on a framework for a new round of talks aimed at lowering tariffs and other steps to free up world markets. Those talks are now on hold for an indefinite period.

At home, the situation highlights the immense political difficulty that President Clinton, an ardent free-trader, faces in creating consensus among fractious Democrats over how to cope with the impact of globalization. Clinton himself acknowledged, "I haven't even succeeded in bringing harmony, I know, within my own party about this."

The Seattle street protests were also a milestone in the ideological transformation of organized labor, especially the hard-hat industrial sector, as it has moved from the ideological center-right to the left. Once a bastion of conservative support for the Vietnam War, opposition to affirmative action and backing for Richard M. Nixon's "Silent Majority," the union movement has now become the ally of once-disdained environmentalists, animal rights advocates and other groups on the left.

"The boat just capsized, and I think that any intelligent political candidate needs to step back and ask: How ought it [trade agreements and organizations] work?" said Carl Pope, executive director of the Sierra Club.

But the generally liberal and Democratic-leaning alliance of labor, environmental groups and human rights activists faces a problem as the 2000 election approaches: It has no horse in the contest for the Democratic nomination.

"It's Tweedledee and Tweedledumber," said Lori Wallach, director of Public Citizen's Global Trade Watch, referring to Gore and former senator Bill Bradley. Both Gore and Bradley are proponents of free trade, although both have said they would support direct inclusion of specific language setting labor and environmental standards in future trade agreements.

The one candidate who stands closest to adversaries of the WTO is Patrick J. Buchanan, the former Republican now seeking the Reform Party nomination. Buchanan's adamant opposition to gay rights, abortion rights and a host of other litmus-test liberal issues makes him anathema to environmentalists and human rights activists.

"Ninety-nine-point-five percent of those people are more likely to buy a pair of Nike sneakers with 'Sweatshop Made' imprinted on the back, eat a drowned dolphin tuna sandwich and vote Republican before they are going to vote for Pat Buchanan," one key leader of the protests said.

Russ Verney, Reform Party chairman, sought to capitalize on the controversy, declaring that after leading peaceful demonstrations "to protest what this administration had created, and because Al Gore was missing in Seattle, organized labor should withdraw immediately their endorsement of Al Gore. Otherwise it is a contradiction in terms: They were out protesting themselves."

Republican political strategists contend that the trade issue is problematic for both parties, but much more severe for the Democrats. "Both parties have these factions [opposed to international trade agreements and organizations], but it is much larger on the Democratic side," said David Israelite, political director of the Republican National Committee.

Democratic proponents of free trade and the WTO tried to put the best face on the outcome, but acknowledged that intraparty conflicts have been exacerbated.

"The opposition has arisen. . . . The big fault line in our party is between the people who believe that trade and open markets are essential to our continuing prosperity and those who fear it and want to stop it," said Al From, head of the Democratic Leadership Council. "We will see if the people who can put protesters in the streets have enough popular support to stop a major initiative" when Congress takes up a proposal to grant permanent normal trading status to China next year, he said.

Simon Rosenberg, executive director of the New Democrat Network, contended that labor and its allies "may be doing the thing that ensures that we don't win the House back in 2000. . . . The challenge for us in 2000 is if Democrats come out against WTO and other trade matters, can we maintain our strength in swing states and districts where it is critical to be on the side of prosperity and growth."