An idiot, dolt, someone who talks incessantly about things they are completely wrong about.
Wow, that Rachel Maddow is a real slewsie.
or
Wow, that Rush Limbaugh is a real slewsie.
Noun: Dumb to the point of ignoring factual evidence rebutting an argument. Obstinately stupid.
Adjective: To make oneself appear incredibly uneducated and obtuse, either intentionally or unintentionally.
noun: The definition from Webster's right in front of him, he was too slewpid to ascertain the meaning.
verb: The slewpid blogger didn't understand his posting invalidated his point.
