The idea that we're in a "capitalistic society". Every country in the world lives somewhere on the spectrum between capitalism and socialism. The US is further towards the capitalistic side than Europe, but we've plenty of non-capitalist aspects of our society.

We already accept a wide array of socialist policies in the form of Medicare, Social Security, etc. We've also plenty of evidence from the rest of the developed world that the socialist approach to healthcare provides similar outcomes at greatly reduced cost. "We're capitalists, deal with it" is a fundamentally silly reason to avoid healthcare reforms.