PASSPORT LAW MAY ENTICE MORE ILLEGALS.

Byline: BRIDGET JOHNSON

SHORTLY before Christmas, as new Mexican President Felipe Calderon was visiting the border at Nogales to announce his plans for decreasing northbound traffic, I headed south across the border to Tijuana.

It's a pleasant day-trip ritual for Californians in need of some sun and cerveza: Park your car at one of the large lots north of the border crossing to spare your car from auto thieves or the manic driving in Mexico. When you cross through the turnstyle and pass into Mexico, you might encounter one cop sitting on a folding chair, as opposed to the gantlet you face coming the other direction.

Cross through a plaza and over the extremely polluted Tijuana River footbridge, and it's about six blocks to the main tourist drag, Avenida Revolucion, where mischief can be found as easily as dollar tacos. Catering mainly to Americans, many signs are in English, prices are advertised in American dollars, and salesmen in front of stores know all the key phrases to try to lure customers inside.

When the shopkeepers start offering free massages with purchase (no kidding), you know they're trying to move merchandise (or just make a move). But Tijuana was especially devoid of tourists when I was there, both on Revolucion and in an artisans' mercado I frequent.

One shopkeeper commented on the lull as I browsed through ceramics: ``It must be the cold,'' she said on a sunny, perfect, 68-degree day.

Any drop in the cross-border flow hits businesses here hard, continuing down the coast to Rosarito Beach and Ensenada, or further inland at the famous brewery border town of Tecate. More than 22 million foreign visitors spent $12 billion in Mexico in 2005.

While the shops were empty, the line to get back into the United States was as long as I'd ever seen it, including many Mexicans waiting to cross over for the holidays. As vendors worked the line, selling pork rinds and sweet bread, I mused that it would probably save time to pay a ``coyote'' to smuggle me across.

When one finally arrives at the Customs and Border Protection counters, an agent scowls at your driver's license, questions you about your citizenship, asks what you're bringing into the country and then lets you proceed to an airport-style screening machine for all bags.

It won't always be this way. On Jan. 23, via 9-11 Commission recommendations, begin new requirements that air travelers must have a passport to enter or re-enter the U.S. from Canada, Mexico, Central and South America, the Caribbean and Bermuda. The State Department has been aiming to have the same passport requirements in place for land travelers by Jan. 1, 2008, though recent legislation gives leeway for implementation.

This wouldn't seem like such a big deal except for the fact that Americans are not passport people. Less than a quarter of Americans have passports, and they're not a force of habit, but are usually acquired by necessity for jobs or should someone finally save up for that European vacation.

So will college students, prescription-drug seekers, church groups and shopping-and-cerveza fans like me pony up $97 for the passport, or find someplace else to go? It's not like California has a dearth of recreational activities, or even lacks the same great authentic Mexican food found to the south.

And how, I wondered as I bought a fresh bag of churros from a street vendor, will that affect the scores of entrepreneurs whose livelihood depends on the regular tourist flow?

Calderon, in his Nogales visit, stressed that better job opportunities need to be present in Mexico to curb the exodus north, a no-brainer that's been a long time coming. Hopefully, this president will do a better job of addressing the root cause of the illegal immigration problem.

Since his stormy Dec. 1 inauguration, Calderon has also jumped on problems that have dented the tourist trade this year by clamping down on the leftist protests in Oaxaca, where the U.S. had recently elevated a travel warning, and drug-trade killings in Michoacan state.

But everyday Americans going back and forth across the border play a big role in helping Mexico get the most out of its tourist industry, and helping the artisans and entrepreneurs in these towns make ends meet.

And if we interrupt that cash flow, should we be surprised if many cross through the desert and take under-the-table jobs that have flourished unchecked in the U.S.? Because if Muhammad won't come to the mountain...