Intelligence is correlated to the ability to adapt to different environments and circumstances. The higher the intelligence, the easier it is to deal with ambiguity, incomplete information, and to make intuitive leaps in logic that turn out to be productive and right. The lower the intelligence, the less likely it is to adapt to change and the less likely it is for that organism to be successful in the new and changing environment.
Democrat politicians tend to lack the ability to deal with ambiguous information, to make correct intuitive generalizations, and therefore seem to lack the basic intelligence needed to adapt and survive. This is why the Democrat party is slowly losing favor due in large part to a failure to deal effectively with changes taking place in the political landscape, and this failure to adapt is directly correlated to the general lack of intelligence demonstrated by Democrats.
The act or habit of making statements based on pride, self-importance, conceit, or the assumption of intellectual superiority and the presumption of knowledge that is not in evidence or supported by any facts or experience.
"The War in Iraq is similar to the War in Vietnam" stated by Howard Dean is based on Dr. Dean's arrogance and self-importance, and not based on any understanding of current events or direct knowledge of the situation in Iraq.
Senator Kennedy repeating "Lie after Lie after Lie..." is evidence of his arrogance that seems to derive from little more than his family name, and not from his knowledge of the subject matter, or his understanding of events.
Contrast this to ignorance -- for example, claiming that Islam is a Peaceful Religion when in fact the religion is only peaceful to others who submit to it (the meaning of "Islam") and even then it is not peaceful to other "believers" who belong to different Islamic sects. This is not an example of arrogance as much as an example of ignorance, but the act of making such claims is similar to arrogance.