As I tried to tell Aus, Capitalism does not exist on a sliding scale, the smallest touch of socialism eradicates the Capitalist system - the free market - and turns it into a Mixed economy. So when you say that the US has a mixture of socialism and capitalism, you are not only incorrect but you also reinforce the Left's fallacious beliefs.
Put yourself in the mindset of a Leftist. What is it they blame when the econ tanks? Capitalism, i.e. the private sector, those evil bankers, greedy Wall Street Tycoons, big business etc. What do they credit for good economic times? Socialism, i.e. the public sector, the beloved Unions, and the government's infallible ability to guide the economy to prosperity while keeping the greedy Capitalists at bay.
Naturally, the Leftist "solution" for every economic problem is... More Government! After all, it has to be larger and more powerful to overcome the nefarious machinations of the evil private sector, all those selfish Capitalists who made their fortunes by lying, cheating, and stealing their way to the top must be kept on a short leash, and watched at all times, or they will crash the economy. Government to them is as pure as the wind driven snow, uncorrupted by the profit motive - the vile curse of the private sector - Unless of course Republicans have power, then government is just a tool the crooked politicians use to steal money from the poor so they can give it to their rich crony friends.
Bottom line, we don't have Capitalism in the US and suggesting that it can exist in degrees will only fuel the fallacy of the Left. While Capitalism doesn't exist on a sliding scale, economic freedom does. Who is more free, the man confined to a prison cell or the man standing in a field shackled with leg irons? The man wearing the leg irons can be more productive, he has the capacity to provide products and services to others, while the man in the cell cannot. Capitalism is Freedom, no chains, no cells, no government impediments (or assistance) whatsoever.
Our system is one of shackles but Americans have become so accustomed to wearing them that they forget they are there, or consider it necessary and rationalize the shackles as being better than confinement inside a prison cell. We don't even consider ourselves a "Free" nation anymore but merely the "Free-est", a subconscious acknowledgement of our subjugation. What has been lost is the idea that Americans can be free, that we can cast off the shackles and live our own lives without the government holding us back from prosperity, or dragging us over the cliff. So please, do not confuse our lesser degree of slavery for that of actual freedom, do not confuse the absence of totalitarian Communism for the presence of Capitalism.