I can't believe you Americans are so?

Divided I mean I know there were always people who liked one party or the other but name calling and petty bickering (I know i'm guilty too I got caught up in it ) I have to ask why do you think this Governments terms have divided the country so bitterly ?? It has even strained the Canada US Relationship,, Whats going on here?? Is it the War ?? or is it something else ?? Please think about your answer..