Some interesting and valid points are made, especially in regards to Healthcare.
I would also agree with the article that the extreme right is far more powerful than any extreme left.
However I don't think what we need is more extreme partisanship.
The author claims that the reality of American politics is extremism and we should just accept that. They say would-be centrists 'retreat into a fantasy world', whereas I would argue that extreme ideologies on both the left and right are far more idealistic and delusional.
If you want to push politics to the left, the answer is not to be more extreme - the answer is to be a more reasonable leftist that appeals to more voters.