Arrogance

[Myrddraal]

Arrogance often manifests itself by being disparaging of those you disagree with.

Go with Kukri's way, not only will you annoy people less, but if it turns our your source of info isn't infallible, then you'll make less of a fool of yourself. It's a good feeling to bring an arrogant person down a notch or two.

For example, what if you had said to this guy "I can't agree with your policy on x and y" rather than "I didn't vote for you", maybe he'll defend his ideas, and who knows, he might actually have something to tell you you didn't know.

Just assuming that you were right to not vote for him, end of discussion, is what is arrogant in your behavior I think.

EDIT: but LittleGrizzly is also right imo, it's a balancing act