In 1970, income and wealth inequality were at historical lows. The income tax tables had over 25 brackets with the top marginal rate of 74%. Campaign funding was limited to the presidential campaigns and lobbyists were few and far between.
After the Brown v Board of Education the development of ideas to resist federal laws was initiated. Read Democracy In Chains for details which also includes who funded this idea development like the Koch Brothers.
In 1971, Lewis Powell wrote a memo at the request of the president of the US Chamber of Commerce. This memo laid the foundation for corporate intrusion into our political process.
In 1970, for the second time in our national history, a law, called the Congressional Reorganization Act of 1970, was passed that changed the way Congress operated. This act is what enabled the massive growth in lobbyists, changed how our laws were written, and enable organizations like the NRA to keep laws desired by the majority from becoming law.
Listen to Congressional researcher James D’Angelo as he explains how the Legislative Reorganization Act of 1970 opened up politicians voting records and has helped special interests and corporations put profit before people: