Note that you could apply the exact same principle to argue that legislators should be lawyers. After all, if you're not trained in the law, how can you possibly write a law? Or understand the many subtle ramifications of the law that someone else wrote that you're voting on? And why stop at legislators? Why not accept, say, literacy tests? How can a citizen possibly make an informed choice at the ballot box if they can't read a newspaper?
The point I'm trying to make is not that electing judges is good, only that it is, at least in the U.S., a direct consequence of democracy. You may decide that democracy is more trouble than it's worth, and cite this stupidity as evidence. But what you cannot do is say that electing judges is stupid and also that you believe in democracy, because in the U.S. the one has followed directly from the other.
And note well: I am not advocating literacy tests. I am only pointing out the logical consequences of adopting the principle that judges should have special training.
BTW, one of the reasons things are the way they are is that the "indigent and commoners" don't necessarily believe they'll get a fairer shake from someone who has a JD from Harvard than someone who doesn't.
As a Canadian, even after living in the US for over a decade, I find your comment baffling. For better or worse, the law is a complex subject both in jurisprudence and process. If judges can be significantly less knowledgeable than the attorneys that appear before them then how can the law be applied equally?
The US Constitution guarantees equal protection under the law yet how can that be realized if there are no minimum standards that apply to judges?
Two things that I cannot understand about the US: the election of judges and outright politicization of the mechanics of voting.