huffington post is probably as far left as you can get in an online publication
For example, he proposed taxing vehicles imported from Mexico by semi-American companies like Ford. That's not exactly the free trade GOP party line.
http://www.detroitnews.com/story/news/politics/elections/201...
Not everything that disagrees with the dominant position of the Republican Party is "far left".
There has been bipartisan support on Capitol Hill for TPP and TTIP. Free trade hasn't been particularly left or right recently.