I remember encountering a word (it was a neologism, not a popularly accepted word) that meant something like "having-a-strong-but-completely-uninformed-opinion". It might have been the related idea of "arguing-vehemently-without-really-knowing-what-you're-talking-about".
I wanted to use this word recently (political climate, doncha know), but couldn't (and can't) remember it. Can anyone help me recall?
Example usage (pretty sure it was an adj):
Geez, the commenter on that thread is so ________.