How would the political process change if congressional districting were organized by strictly geographic principles instead of by the political process in state legislatures?

The electoral districts would be more competitive. The "safe" districts established by gerrymandering would not exist, which means that each individual vote would count more. It would also mean that representatives would need to be in touch with the needs and desires of all their constituents.

Worcester v. Georgia

Explanation:

On review of the case, the Supreme Court in Worcester v. Georgia ruled that because the Cherokee Nation was a separate political entity that could not be regulated by the state.