(FORTUNE Magazine) – You've seen this drama before. An important trade vote in Congress. Huge mobilization efforts by business and labor. Desperate meetings in Capitol suites and the Oval Office. Late-hour agonizing by lawmakers. All that plus this: The trade bill gets approved. No other form of legislation is so frenzied yet so predictable.

Right now passions are high about establishing permanent normalized trade relations with China. President Clinton is counting on a large majority of Republican votes and is scratching for sufficient Democratic support. The vote in the House is too close to call. But hold the suspense, discount the pleadings of religious groups, play down the warnings by organized labor and environmentalists. In the end, lawmakers will look at the dollars involved and conclude the legislation makes sense.

Here's why. In the weeks leading up to a vote, practical elements favoring trade legislation begin supplanting theoretical arguments against it. Washington lobbyists finally win the attention of CEOs, who finally call their Congressmen. Large war chests come together, this time underwritten partly by high-tech companies, even those victimized by Chinese software piracy. In a robust economy with low unemployment, it's hard to whip up a frenzy about imports jeopardizing American jobs. Besides, lawmakers begin to worry about markets for hometown products.

Clinton has made a dozen speeches promoting the legislation since December. Four Cabinet members are pressuring waverers. Though labor has created phone banks and distributed fliers, Peggy Taylor, the legislative director of the AFL-CIO, says, "The other side's money is way beyond ours." The Chamber of Commerce sent 17 capital lobbyists and a dozen regional staffers into the field to meet with 70 undecided lawmakers during the two-week spring congressional recess. All the lobbying money involved, plus all the money at stake in a market bigger than all the tea in China--maybe $13 billion--will tip the balance to the free traders.