Combine tequila, lime juice, olive oil, chili powder, cumin, garlic powder, and salt into a large, resealable container. Add chicken, and stir well to combine. Refrigerate for at least 30 minutes or up to 24 hours.
Heat a medium skillet over medium-high heat. Pour chicken with marinade into hot pan, and bring to a low simmer. Reduce heat to medium-low, and cover. Cook, stirring occasionally, for 15 minutes or until chicken is cooked through.
Shred chicken with two forks, and simmer for a couple minutes longer to allow flavor to penetrate meat. Use a slotted spoon to serve.
Assemble tacos with warm tortillas and desired toppings.