This little tableau, enacted dozens of times last week with uncommitted House members, illustrates why it’s been such a touch-and-go battle bringing China into the World Trade Organization. But it also shows why the bill–which guarantees Beijing “normal” U.S. tariffs if it lowers its own trade barriers–is likely to pass in a House vote at midweek. Big Business, which has been out-lobbied by labor in recent free-trade fights, is pulling out all the stops this time to gain access to China’s vast market as part of Bill Clinton’s WTO deal. It is spending tens of millions on pro-PNTR ads, bullying congressmen in power plays, targeting local districts. “We would have mortgaged the building if we had to,” says Tom Donahue, head of the U.S. Chamber of Commerce.

Most congressmen agree the arguments in favor of PNTR are overwhelming. But with a hot contest to win control of the House in November, they fear political fallout from labor’s grassroots assault on the deal. That’s where U.S. industries from agribusiness to Silicon Valley have been decisive. Most corporate lobbyists aren’t saying so outright, but their message is clear: buck us now and you may not get our bucks in the fall. “We made very clear that this is the vote for business this year,” says Chris Padilla of Kodak. That’s been a major factor, especially for the 150 or so House Republicans expected to carry the bill along with about half as many Democrats (the Senate vote is considered a shoo-in).

Business has helped sway key players like Tom DeLay, the fiercely partisan GOP House whip. Not known as an internationalist, DeLay is also one of those, notes former ambassador to Beijing James Lilley, who “cringe” at “giving Clinton this kind of victory.” A senior administration official, asked whether DeLay was persuaded by the business lobby, replied: “I can’t think of any other reason.” (DeLay says he’s for it only because it’s good for the nation.)

Business’ impact was felt too on the other side of the aisle, where the high-tech lobby has been especially brazen. When House Democratic leader Dick Gephardt came out against the bill last spring, Silicon Valley executives threatened the Dems with a cutoff of funds. Gephardt’s people began emphasizing his low profile on the issue. Says spokeswoman Laura Nichols: “We’re not by any means ‘whipping’ it”–rounding up votes against it. Why? She says Gephardt wants members to vote “their conscience.” But he also worries about losing a House election that could make him speaker next fall.

Late last week a top anti-PNTR strategist conceded the fight was all but over. He said the most opponents could hope for was that, after Taiwanese President Chen Shui-bian’s inauguration on Saturday, the Chinese might tar themselves by threatening Taiwan again. But the U.S. business community may have that prospect covered as well: among those who went to Beijing recently was ex-assistant national-security adviser Sandra Kristoff, who now works as a lobbyist for New York Life. Her message to the Politburo: pipe down. That, and business’s decision to pipe up, may well carry the day.