I stated it a little tongue in cheek but I do believe our gov't is overly protective of their lobbyist and financial base at the costs to the average American. I believe whats best for America, not you or I, is the best action to take. So, you or I might lose some in a policy if its in the best interest of the country, we might win some. Many people only look at themselves and see what they get out of it and complain if they don't win. That's my personal view to almost all policies. Country first, individual second.
As for the term its defined "Corporate oligarchy is a form of power, governmental or operational, where such power effectively rests with a small, elite group of inside individuals, sometimes from a small group of educational institutions, or influential economic entities or devices, such as banks, commercial entities or lobbyists." It states "effectively" rest not exclusively or solely rests with. And with this, have you ever really looked at a spending bill or policy and see who/how it effects. They are loaded with incentives based almost exclusively with their powerful lobbyist, usually not to the benefit of the country.
So, I wouldn't necessarily say 'corporations' I would say the wealthy. It is a threat to democracy. While the ultimate power appears to rest with the people -- after all, we do vote for our politicians -- the candidates available to us need to have appeased wealthy donors enough to stand a chance.
In essence, the wealthy pick the candidates for us, and then we vote from their pick. There's simply no manner, or very little manner (it does happen from time to time) for your average citizen to have a chance at being elected, money crowds them out.
I took this from another site:
For example, in the 2012 election (record spending, not something to be proud of) Super-PACs made up approximately 85% of the content Americans saw. Of those Super-PACs some 90+% of their funding came from ~200 individuals. Just think about that: 200 people were controlling virtually everything the entire country saw about the election. Wealth concentration in the hands of a few, a ruling aristocracy, is bad for our country.