Heat the oil in a medium saucepan over medium heat.
Add the onion, garlic, chipotle, chili powder, and salt. Cook until the onion softens, about 15 minutes.
Add the chicken broth and bring to a boil.
Reduce the heat slightly and simmer, uncovered, for 10 minutes.
Add the corn and cook for 5 minutes more.
Remove the saucepan from heat and stir in the tomato, chicken, cilantro, and lime juice.
Divide the tortilla chips among 4 warmed bowls.
Ladle the soup on top of the chips and serve with lime wedges.