Does it have to take a tragedy?

ALERT listeners probably picked up the several references to Mexico during last week's debate among Democratic presidential contenders. But unfortunately it seems to take an event of the proportions of the tragic loss of 18 Mexicans, asphyxiated last week in a locked boxcar in Texas, for Mexico to claim a place - however briefly - in public consciousness north of the border.

These young men, many of them married, with children, were heading north in search of economic opportunity that simply isn't available in their hometowns. Such work as is available - construction or farm labor - does not pay enough in Mexico to support a growing family. Even trained professionals - like accountants - often fail to find employment in Mexico.

The border regions of Mexico, tied in as they are to the economy of the United States, are enjoying a certain boom; Tijuana's unemployment rate is 1 percent. But the 19 locked into that Missouri Pacific boxcar - one survived by punching a breathing hole in the floor of the car - were mostly from deep into Mexico, far from the maquiladora factories, where (largely female) workers assemble electronic components and other such products for reexport into the United States.

Nowhere else does the third world look at the first across such a long and essentially undefended border. With no opportunity at home, the pressures on young Mexicans to migrate are irresistible.

And yet Mexico is too rich in potential to be written off. The country needs the encouragement of its global neighbors, including the big one next door, to launch a major new economic advance.

American interest in Mexico seems to run in cycles. If last Wednesday's debate was any indication, another cycle may be about to start. The next administration in Washington - whether Democratic or Republican - will have a good opportunity to launch a new Mexico policy.