Combine first 8 ingredients in a small bowl, stirring well with a whisk. Place in a large zip-top plastic bag. Add pork to bag; seal. Marinate in refrigerator at least 2 hours, turning occasionally.
Place pork and marinade in an electric slow cooker. Cover and cook on low for 8 hours.
Remove pork from slow cooker using a slotted spoon; place on a cutting board or work surface. Cover with aluminum foil; keep warm.
Add broth to sauce in slow cooker. Cover and cook on low for 30 minutes or until sauce thickens. Shred pork with 2 forks; serve with sauce.