We made structural changes to our government in the 1920s-1930s and this is one of the long term effects.
1. Congress on its own decided that 435 representatives was "enough" and ceased apportionment. Since then representation has diluted from approximately 100000:1 to 1000000:1.
2. We changed the way the Senate was elected, from a majority of each state's legislature, to a popular vote.
The result is that we have effectively created 2 Senates. Winning a majority vote of so many people requires massive funding. Hence, the profound corruption we live in today.