I agree with this. I would like to give credit to a couple left leaning posters though. Doc Brown and K9 improve the discussion here. Though I don't always agree with them, I appreciate how they are willing to have debates with others. I enjoy having my beliefs challenged by reading their informed opinions.
To your point, when their opinions don't fall in line with the other resident lefts, there's not much debate. They get shouted down and called right wing. It's very disappointing. Some of the other left leaning posters could learn a lot by having ideological debates with their own side. I certainly know I could learn from it. That's why I come here.