Pour the diced tomatoes into the slow cooker. Add the taco seasoning and mix thoroughly.Place the chicken in the slow cooker.Pour chicken broth over the chicken until the chicken is submerged in the broth and tomato mixture. Stir to combine everything.Put the lid on the slow cooker and set to low. After 4-5 hours the chicken will be fall apart tender.Use a fork to remove the chicken from the slow cooker. Shred with two forks.Use a slotted spoon to scoop the tomatoes out of the sauce, and add to the chicken. Add about 1 cup of the liquid from the slow cooker to the chicken and stir. I discarded the extra liquid in the slow cooker, and returned the chicken to the slow cooker and set to the keep warm setting during the party.