I heard a brilliant description of political extremism in college, and it has stuck with me all these years later:
Both extremes say the same thing; they just word it differently. The "Conservative" says, "I understand Absolute Truth. Anyone who disagrees with me is wrong." The "Liberal" says, "There is no Absolute Truth. Anyone who disagrees with me is wrong." The only real difference is how narrowly they draw their circles.
Meanwhile, those of us who live somewhere in the middle end up getting rejected by both extremes, since we share various views with both. The extremes, however, rarely recognize and acknowledge shared ground; rather, they focus on differences - ridiculing all who don't agree completely with everything they believe.
I don't know how many times I've had someone who is more liberal than I call me a conservative - or how often someone who is more conservative than I call me a liberal. Occasionally, it's really frustrating; generally, it just is amusing.
"At the extremes, a liberal is just a conservative with more friends."