Preheat the oven to 400°F. Wash the potatoes, pierce the skin a couple of times to help it release steam while baking. Place the potatoes directly on the middle rack, bake for approximately one hour or until internal temperature is 210°F.
In large nonstick skillet, over medium-high heat, heat oil. Add ground turkey; cook, stirring to break up large pieces until lightly browned, about 5 minutes. With slotted spoon, remove turkey from skillet, set aside.
To skillet, add onion, bell pepper and garlic, cook until vegetables are tender-crisp, about 4 to 5 minutes. Add chili powder; cook, stirring, 1 more minute.
Stir in kidney beans, stewed tomatoes, 1/4 cup water and salt. Bring to a boil and add the turkey, then reduce heat; simmer until thickened, about 10 to 12 minutes.
Halve potatoes lengthwise, cutting almost to base of the potato. Mash slightly with fork, leaving in skins. Spoon chili mixture over each potato, dividing evenly. Top with cheddar cheese and sour cream.