I believe the root of the "not a free market" idea comes from the fact that currently if you are wealthy enough, you can "buy" a politician so that they back up

I believe the root of the "not a free market" idea comes from the fact that currently if you are wealthy enough, you can "buy" a politician so that they back up policies that enable subsidies and tax breaks which are convenient for you. Tit-for-tat, like you said. In a sense, there is actually a free market... but it's the one where you buy and sell politicians. That one conditions the other one, which isn't free. That will happen regardless of who lives in the White House.