Where Will the2008 Presidential Race Be Decided? A. The Northwest; B. The Southwest; C. The Plains States; D. The South; E. North-South Border States.(Cover story)

Byline: Howard Fineman

In the wide southwestern arc of the country, which stretches from Fresno, Calif., and Las Vegas through Phoenix and Albuquerque, N.M., to Houston, millions of Americans--and millions of want-to-be Americans, here legally or illegally--rise each morning to the cheerful Spanish of a 36-year-old Mexican who arrived here 20 years ago in the trunk of a car. "Despiertese! Despiertese!" says Eduardo Sotelo. "Wake up! Wake up!" Known by his nickname, "El Piolin," or "Tweety Bird" (stuck on him in childhood for his small stature), Sotelo fills the hours on his syndicated Spanish-language radio show with immigration advice, Mexican ranchero tunes, mischievous prank calls and exhortations to face the day's labor with gratitude to God and America. "Why did we come to this country?" he asks his devoted audience of 11 million listeners a week. "To succeed!"

In recent months, he's added a new bit to his show--an exhortation to get involved in politics. He urges legal residents to apply for citizenship so that they can vote; he asks his listeners--most of Mexican background--to support immigration reform. As one of the country's highest-rated and most influential media personalities, in any language, Sotelo inspires listeners to walk the walk when he talks the talk. Backed by his employer, Univision Radio, Tweety Bird flew to Washington from his home base in Los Angeles in June so that he could present Congress with a million letters in support of the then pending immigration bill.…