WASHINGTON - On a November night in 1989, San Diego County resident Muriel Watson drove her white Buick to the Mexican border and joined 22 other motorists in shining their headlights into the darkness as a highly visible statement against illegal immigration.Although her initiative, known as ``Light up the Border,'' grew dramatically over the next year, the participants were mostly local. Concern about illegal immigration back then was largely limited to California, where nearly half of all undocumented Latinos made their homes.``I made many lobbying trips into Washington and talked to many congressmen from many states . . . and...