[old republic]

Repeal the 17th amendment it was silly. The Progressive argument for the 17th was to prevent corrupt state legislatures from sending corrupt Senators to Washington. But I say that it is harder to corrupt a whole legislature than a single man. It is harder to buy two houses of a state legislature than it is to directly buy a single Senator.

[Cheburashka]

The people who backed the 17th amendment had examples they cited. If I remember correctly, one was the California legislature, which was in the back pocket of the railroads.
I suggest doing some research of your own on the subject.
That said, I am still in favor of the repeal of the 17th Amendment. But don't think that there could not possibly be a downside.
And as I said in a post above, I truly doubt that the American people, having amended the Constitution to give themselves the right to directly elect their Senators, will give up that right under any circumstances. Until I see some real evidence to the contrary, I truly doubt this will ever happen.