TOMORROW President Bush's trade representative, Robert B. Zoellick, will sign the Central American Free Trade Agreement. Relative to the grander parts of the administration's trade agenda, such as a Free Trade Area of the Americas or global trade liberalization, the Central American agreement is not a momentous breakthrough. But the five countries of the region nonetheless imported more U.S. products than Russia, India and Indonesia combined last year, and the trade deal means a lot to a struggling region that is close to the United States and the source of many migrants. When the Dominican Republic joins the deal, as it is expected to do shortly, the six-country bloc will represent the second-largest export market for the United States in Latin America, behind Mexico.

There are fair criticisms of the deal. It is heralded as a job-creating economic boon, but regional trade deals mainly just shift jobs from one U.S. trading partner to another; in this case, Central American apparel manufacturers will gain at the expense of Asian exporters. It is billed as a free trade agreement, but then it hypocritically sets limits on sugar exports to the United States because the Bush administration caved in to the domestic sugar lobby. But the deal's opponents -- including Sen. John F. Kerry (Mass.), the putative Democratic presidential nominee -- focus on a different point. They say it lacks adequate protections for workers in Central America.

It's hard to see how any deal that keeps jobs in the region can be bad for the people who work there. At the end of this year, the global system of textile quotas that has restrained Asian exporters will expire, and jobs are liable to migrate from Latin America unless the region gets preferential access to the U.S. market. As well as providing that, the deal also creates a panel that would hear complaints about the non-enforcement of labor laws. Fines levied by the panel would be used to improve enforcement. These are valuable provisions.

Mr. Kerry and other opponents of the deal believe that the United States should have negotiated even more worker protections. This is part of a larger debate on globalization: As poor countries become part of the global economy, can they be made to accept regulations that prevent a race to the bottom? In principle, this is a reasonable question, and where labor rights are violated harshly, as in China, for example, we believe that the United States should urge better behavior. It is a bad idea, though, to oppose trade deals on the grounds that labor protections are advancing, but not quite fast enough. This neglects the truth that the best way to boost workers' bargaining capacity is to boost job creation, so that labor is in strong demand. Trade deals that create jobs are good for workers' rights as well as workers' incomes.

Opposition to the Central American deal is so strong in Congress, particularly among Democrats, that it is unlikely to gain approval before the election. Congress is saying that it won't support trade with poor countries, even when they are struggling democracies not far from America's borders. Mr. Kerry, whose supporters are quick to cite his history of pro-trade votes in the Senate whenever his credentials are questioned, should not back away from his own record.