Heat the olive oil in a deep pot over medium-high heat. Stir in the squash, and cook until it begins to soften, 5 to 7 minutes. Add the onion, celery, and carrots. Cook until the onion is transparent, about 5 minutes. Stir in the garlic, chipotle peppers, basil, parsley, and cumin; cook 2 minutes more. Mix in the tomatoes and chicken broth. Reduce the heat to medium, and simmer until the vegetables are tender, about 30 minutes. Stir in the cannellini beans and the corn; cook just until heated through.
To serve, ladle the soup into bowls. Squeeze lime juice over each bowl, and top with tortilla chips, a dollop of sour cream, and a sprinkling of Mexican cheese.