Odds of Getting In
Since 2001, the U.S. Customs and Border Patrol has expanded by leaps and bounds (source). From international terrorism to concerns about immigration to just being really, really for or against something, patrolling the nation's borders has become a major focus for politicians and other officials.
Congress regularly approves more money for more agents (over $600 million in 2010 alone), and that means more job opportunities. So as long as you fit the bill (and can also say that in Spanish), there's a good chance an opening is just waiting out there in the desert. Go find it (preferably with a map, GPS, satellite phone, and a lot of water).