Why 2 senators (instead of 1) per state?
Ignoring the 17th, if senators are supposed to represent their state governments, why would there need to be two?
Is it just that one person might get sick or unable to fulfill their duty? And the smaller states would have preferred half a vote as opposed to no vote? Given the communication delay back then, a state government wouldn't have been able to send a (temporary) replacement fast enough for votes?
But even then, why not just make it 1 vote per state where any number of people from a given state can be sent to represent the state government? And if the multiple senators of a given state aren't able to agree (even though they're supposed to just relay the message from the state government), the state has bigger issues to worry about.
Before 1913, were there senators from the same state that voted differently?