As in other federal countries, it makes sense to elect one purely by popular vote, the other by giving each state equal representation.
To pass a law, you'd then need 50% of people and 50% of states to support it.
This is a simpler system for elections, and keeps the power of people and states more balanced.
e.g. Germany uses a very similar system (Bundestag being elected by popular vote, Bundesrat being chosen by each state).
As in other federal countries, it makes sense to elect one purely by popular vote, the other by giving each state equal representation.
To pass a law, you'd then need 50% of people and 50% of states to support it.
This is a simpler system for elections, and keeps the power of people and states more balanced.
e.g. Germany uses a very similar system (Bundestag being elected by popular vote, Bundesrat being chosen by each state).