to add to what u/War_Hamster said, before the 17th amendment the average term of a senator was around 4 year (less than a full term). After the 17th, the average term is something like 23 years. For corporations and other interest groups, senators are more easily bought off now; whereas before, you'd have to buy off a new one every few years, and they might not even be around long enough to do you any good.
States have the power to do this. A massive federal government was the founders worst nightmare
And this is a pretty good segue for my daily public service announcement:
REPEAL THE 17TH AMENDMENT
Not trying to troll but what advantage would having the state legislatures voting for the Senators confer?
to add to what u/War_Hamster said, before the 17th amendment the average term of a senator was around 4 year (less than a full term). After the 17th, the average term is something like 23 years. For corporations and other interest groups, senators are more easily bought off now; whereas before, you'd have to buy off a new one every few years, and they might not even be around long enough to do you any good.