"Historically, the Democratic Party has supported organized labour, ethnic minorities, and progressive reform. It tends to favour greater government intervention in the economy and to oppose government intervention in the private, noneconomic affairs of citizens"
The Republican party historically stood for laizzes-faire economics, minimal government, minimal government spending/programs, etc.
Basically, the Republican party of old was much like the Libertarian party of modern times. Sadly, they have been severely corrupted and twisted over time.
Today, the Republican party essentially is full of rich white men who oppose civil rights/personal freedoms/etc and are in the pocket of large corporations. They closely mirror Fascism/corporatism economically but don't really have the dictatorial tendencies of Fascist governments (although recently passed laws such as the "Patriot Act" have effectively legalized many things which Americans historically would have considered oppressive). However, there are some Republicans who support "classic" Republican views (Ron Paul, to an extent), but many of those people have migrated to the Libertarian Party.
Today, the Democrats are somewhat split. There are the "classic liberals" who support many of the same ideals espoused historically by the Republican party. Unfortunately, it seems that the majority of Democrats are seeking to create a "nanny state" and essentially seek to regulate many private affairs of citizens. Democrats also have strong corporatist leanings, but try to hide them.
To a non-American, both parties would appear right of center. I saw an article a few weeks ago comparing the perceived political spectrum between the US and the UK. Even the US Democratic party would be considered "right of center" in the UK, while "slightly liberal" UK parties would be seen as "extremely leftist" in the US (to the point of being called "communist").
