left-winged nut
A left winged nut is someone that is a liberal extremist.
There are somebody that is overly vocal about their opinion, and is confident that it is the correct one.
There are somebody that is overly vocal about their opinion, and is confident that it is the correct one.
Many people refer to Al Gore as a left-winged nut, especially after his controversial movie, "An Inconvenient Truth," where he skews data pertaining to the effect of Global Warming.