That's the problem with Progressives (at least the heartfelt ones), they actually THINK they can SOLVE corruption.
Corruption is the very nature of Government. The Constitution and the procedures within it are meant to limit and disperse the concentration of the corruption amongst factions.
When the Founders choose the State Legislatures as the body to appoint Senators, they KNEW that localized corruption and local factions (local/state corporations and other monied interests) would be dominant in the selection process. However, this method LIMITED it to interests WITHIN the STATE only. This insured that State itself benefited from their choice.
This also gave the States a direct way to counter the encroachment of the Federal Government, because they would JEALOUSLY guard THEIR POWERS. Many of the best and most outstanding arguments AGAINST nullification were DEPENDENT upon this method of choosing Senators. The idea being that the States could recall their Senators and replace them with new ones in order to block an overbearing Federal Government. Notice how small the federal government was BEFORE the 16th and 17th Amendments (both passed in 1913). Ever since the 17th Amendment was passed, all of the strong arguments against Nullification have evaporated; thus, in some sense, the 17th Amendment LEGALIZED Nullification in order to PEACEFULLY enforce the 10th Amendment; because now the States have NO other PEACEFUL method to enforce the 10th Amendment.
(back to the previous paragraph) With the passage of the 17th Amendment, the LIMITATION keeping this corruption WITHIN the State was eliminated. Now Senators were beholden to NATIONAL and INTERNATIONAL interest groups. This makes them LESS ACCOUNTABLE to the People of the Several States.
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Also, riddle this:
Since there already existed a Popular House (House of Reps), if the People choose wrongly in the House, what makes you think they would choose correctly for the Senate during the same election cycle? Notice how the Senate, even now, is staggered in 6 year terms, just to make sure the People didn't devour themselves in a single election cycle.
So the riddle:
"If one House is Elected by the People, why should there exist another House that is also elected by the People?"