Try to imagine an ideological 50-yard line, a perfect middle-of-the-road position that represents the median of American political thinking at any given time. George W. Bush falls as far to the right of that line as any president in memory. Bill Clinton sat a little to the left of that line; FDR was about as far to the left as Bush is to the right. In modern history, challengers have been most likely to beat incumbent presidents or vice presidents when they seemed to reside the same distance from that 50-yard line as their opponent. If you're trying to unseat a moderate, swing voters are key. Your best bet is to run as one yourself. But moderates don't beat extremists--extremists do, by motivating their base.
Call it Rall's Rule of Ideological Counterbalance.Excerpted from:
http://story.news.yahoo.com/news?tmpl=story&cid=127&ncid=742&e=7&u=/030807/7/4wps0.htmlMakes a good argument here. Very interesting...