The 17th Amendment was a disaster to the Union, but a boon to the so-called “progressives” who from their earliest days wanted a federal government with more general power (and of course “more” is never “enough”).
With the 17th Congress was cut loose from any mechanism to restrain it from honoring the 10th Amendment, and indeed the whole of the Constitution, save for what was politically fashionable at the time.
Once the Court became the Dishonorable Court during the FDR era, a scant two and a half decades after ratification of the 17th (the “progressives” worked fast and they’ve never slowed down since) governance became the playground of the lawless and faithless.
One need only contemplate that an unrepentant Soviet era useful idiot like Bernie Sanders is somehow not considered the socialist extreme Leftwing loon that he is (and indeed is seen by many a better option) to see how inherently dangerous it is to ever depend on political fashion for what government should be doing!
Perfect summary of the problem.