The author is a contributor to Jacobin Magazine which according to Wikipedia "has been variously described as democratic socialist, socialist and Marxist" so it would seem you're spot on.

As far as a critique of the actual paper, it seems to be predicated on the idea that democracy and freedom are synonymous when in fact they're orthogonal concepts. You can have tyrannical democratic structures, in fact that's what the founding fathers sought to combat in the original system they laid out which was less democratic than it is now (e.g. only land owners, people who have skin in the game, can vote).

"When the people find that they can vote themselves money that will herald the end of the republic." – Benjamin Franklin