>And is it really any different here in the U.S as opposed to different democracies?

Somewhat. Search on "proportional representation" Here's one example:
http://www.fairvote.org/pr/

>Or is it really any different now than in this country a hundred years ago?

In one respect that tends to affect our group psychology and our anthropological "in-group vs. out-group" inclinations -- we used to project most all of our demonic imaginings on other countries/cultures, etc. Now that the USSR went out of business, most of our 'enemy' is indentified as among ourselves. Most others are discounted as unimportant. Does that make any sense? Like, if there really was an alien invasion from Mars, we'd suddenly all get along greatly. It's kind of a hard-wired thing in our species' behavior that keeps us splitting up all the time -- this is an adaptive thing that assures variety. Meanwhile, mere 'political' thinking is just a little dot in the waking mind that floats on an ocean of other motivations. Gawd, this is way too much to type about or get into here...