I believe we've moved way too close to a corporatocracy. But I think it has to do with powerful influence by corporate lobbyists and special interests that evade the discipline of the free market though corporate subsidies. Our campaign-finance system is just a system of legalized bribery. But I don't buy that it has anything to do with ideology or belief. IMO you should prefer the Democrats over Republicans. The GOP is completely in the tank for corporations, and the Dems are around half...but the left is all over corporate abuse of power. The right are cheerleaders for corporations and the elite.
Our founding fathers would have never let corporations run our government. The Boston Tea Party was as much a rebellion of corporations like the British East India Company as it was a rebellion against oppressive government
The most destructive Supreme Court ruling in our history was Santa Clara County vs. Southern Pacific Railroad, which created corporate personhood, in essence giving corporations rights that our founding fathers meant only for individuals
Here's a good article on corporations...
http://www.thirdworldtraveler.com/Corporations/Hx_Corporations_US.html
And a website dedicated to the issue of corporate personhood...
http://www.reclaimdemocracy.org/personhood/