This site is owned by the RG and run by Civil Comments.  They use "peer review" and,in addition, upon ocassion, will remove a post which "passed" review but contains comments which don't meet the site's standards.  To my knowledge, those have not been based on "content."  First Amendment rights reference "public" freedoms.  Any "censorship" on a privately owned/operated site does not constitute a violation of the First Amendment.
Were this not the case, virtually every discussion site would be reduced to the "lowest common denominator" level by trolls.

Progressives are hardly communists.  In fact, the progressive movements of the 20th century, especially the New Deal, gave America a 'choice'....a way to address the serious economic issues of the Great Depression w/o resorting to radical measures such as Communism.  I'd be very, very happy to discuss this with you anytime, anywhere.  It would be very interesting.  Give me a call.....I'll buy the coffee or a beer.  Regards, Gary