[bobman0330]

In medieval times, the borders of maps were vague, scary places. Mapmakers drew in crazy monsters with one giant foot, or creatures with their heads in their chests, or, famously, the inscription "here there be dragons."

Even though we have TVs and cars now, the average American (and prob. the average citizen of another country) feels more or less the same about anywhere beyond the borders of the US. Immigrants are weird and unpleasant, China is scary, the Middle East is violent, etc., etc., etc. So, the average American's first response to any problem (terrorism, losing a job, prices going up, wages going down, some cats getting poisoned) is, "Hey, we brought this on ourselves by getting involved with these dragons/Blemmyae/foreigners and look where it got us! We need to curtail immigration/"do something about China"/protect American industry." A recent poll found that two thirds of Americans felt that globalization had hurt America. (!!!!!!!)

Electoral logic demands that both parties cater to this provincial ignorance, and they do. Republicans want to cater to the racists and the law-and-order types, so they bang the anti-immigration drum. Dems want to cater to unions and bleeding hearts, so they bang the foreign-trade-is-bad drum. The root cause is the same: the common man is dumb about economics.

Incidentally, this is why Ron Paul's position on trade is so bad. He may want even more radical free trade policies than we have (and be right to want them), but what about the next guy? If he's elected by Americans, he's likely to be anti-trade. That's why institutional checks on Americans' ability to screw up our economy (e.g., NAFTA, WTO) are so good.