Of course they want to be "called Progressives". "Marxist" is a dirty word to freedom loving Americans. Who isn't in favor of "progress". Who would argue against "progress". "Scata" would like to be called "parfum", but we know it's not.
I am not so sure about "Marxist" being a dirty word in the US amongst the 40 and under age group, if you had a couple of smartly dressed young people at your door espousing Marxist theory you might no be that put out in these drastic economic times. Do Americans love freedom? You guys have voted for some freedom hating Presidents in the last 15 years.