Place potatoes in a large pot of salted water and bring to a boil. Cook until tender, about 30 minutes; drain.
To the potatoes add corn, bell pepper, onion, red pepper flakes and vegetable broth. Boil for about 15 minutes; remove from heat.
In a food processor or blender puree all but 1 1/2 cups of the vegetable and broth mixture with the tofu. Process in batches if necessary. Combine the pureed mixture with the remaining 1 1/2 cups vegetable and broth mixture, and cook over low heat for 5 minutes; do not boil. Season with salt to taste.
