Considered by many to have crushed the first gilded age, the secret ballot was introduced en masse in the US starting in 1890. By 1940 it was everywhere (all citizens and congressmen voted privately). And then for 30 years life was pretty good. Inequality was dropping, so were a number of other metrics, partisanship, campaign finance etc. And then, October 26th, 1970 there was a crack in our air-tight democracy - The Legislative Reorganization Act of 1970 opened up the votes of Congress (the committee of the whole). Dubbed a ’sunshine law’, this bill has only ever been considered a good thing.
The trouble is, we vote in secret for a reason – reasons most Americans forget. Every time votes are public we get massive explosion in two types of electoral fraud. The first form of Electoral Fraud is Vote Buying (Tammany Hall, etc), with as much as 20% of the electorate being paid to vote a specific way (often poor individuals being paid with a chicken wing or a beer). The second form is Voter Intimidation, often times people would vote in the local court house, and they would just announce their vote to the local staff. The trouble with voting publicly (stating your votes to a clerk) is that often citizens were voting on deputies and sheriffs who were sitting right there in the court house, listening. It is hard to vote against an evil Sheriff if he can see how you vote. It is easy to see the problem there.
Interestingly, this is exactly what now happens in our Congress. Inside of congress, voter intimidation leads to massive partisanship and polarization, and vote buying leads to what some congressmen call ‘legalized bribery’. This isn't a correlation/causation issue. This is evidence/proof. The convictions, admissions and stories of this are common (Jack Abramoff, ABACAM, etc etc). And this change in 1970 has led to a feedback loop that responds to the ever increasing money in Washington. Indeed The Legislative Reorganization Act of 1970 is the cause for the phenomenal growth of K-street. And all the big firms were born just months after it passed.